The following rules are a first rough draft of a system to build more complex vehicles for Star Frontiers.  It comprises a system of different parts of a vehicle (each of which has its own Hit Points, Size factor, Weight, Cost, Parabattery/Engine type), so a player can design a vehicle to his desire.  Damage Location tables must be put together, by the GM, for each model of vehicle invented.  This takes a little time, but some of my players enjoyed the challenge of fixing different parts previously not available to them in the rules.  This system is based on the Zebulon Guides rules, but I'm sure they can be used with Alpha Dawn rules as well.  Good Luck.

THE CHASSIS:
 The underframe/skeleton of any vehicle in which everything else is somehow attached.  The Body, Electricals and Mechanical pieces will be added to this section.  So the first thing to do is to decide on what body size vehicle is desired (as well as if it will be ground or air based).
 Damage to this section can only be caused by Mines, Jumps (1d10 per 10 km over Cruise Speed), Crashes (1/4 of the damage done to Body) and by Rough terrain (1d10 per turn unless an off road vehicle, then 1d10 per day).  Below are the tables for Chassis'.

THE BODY:
 The body is the frame that helps construct the appearance of the vehicle, allows
electricals to be run from place to place and as mountings for them and houses the individuals
who will pilot the vehicle.  The Body can be damaged by accidents, gunfire and impact from
falling items.
 Unless the vehicle is armored, any damage from projectile weapons and explosives will do half damage to body and half to passengers [roll or randomly pick victims or use common sense].  Below the HP, size, weight, cost and parabattery/engine type are listed.

TYPE		HP	SIZE	WT	COST	PB/E
Motorcycle:	2 wheel 3 wheel Hover Flit Floater	40 60 80 20 10	S S S S S	1/4 MT 1/3 MT 1/2 MT 1/4 MT 1/4 MT	400cr 500cr 500cr 5000cr 600cr	1 1 1 3 1
Ground/Hover:	Car   Van	200 400 600 300 600 900	S M L S M L	1 MT 2 MT 3 MT 2 MT 3 MT 4 MT	1000cr 2000cr 3000cr 2000cr 3000cr 4000cr	1 2 3 1 2 3
Aircar:		400 800 1200	S M L	2 MT 3 MT 4 MT	10,000cr 20,000cr 30,000cr	1* 2* 3*
Transports:	Ground/Hover   Air	1500 1800 2100 1600 1900 2200	S M L S M L	5 MT 7 MT 10 MT 6 MT 8 MT 12 MT	3000cr 5000cr 7000cr 15,000cr 20,000cr 24,000cr	2 3 4 2 3 4
Explorer:	Command	2000 2500 4000	M L XL	8 MT 12 MT 100 MT	4000cr 6000cr 100,000cr	3/#4 4/#4 2/#4
Glijet:		20	S	1/2 MT	600cr	1**
Jetcopter:	1 man 2 man 3 man Transport	200 300 400 500	S S M L	1 MT 2 MT 4 MT 8 MT	4000cr 6000cr 8000cr 10,000cr	1/1** 2/2** 3/3** 4/4**
Aircraft:	3 man 6 man 20 man 200 man	100 200 500 1000	S M L XL	2 MT 4 MT 30 MT 100 MT	1000cr 3000cr 20,000cr 100,000cr	1** 2**/#2 3**/#2 4**/#3
Special Vehicles:	Tank, Medium Tank, Large Tank, Assault	4000 8000 16000	M L XL	100 MT 200 MT 400 MT	100,000cr 150,000cr 200,000cr	3 4 4/#2
Assault Vehicle:		3000	S	50 MT	50,000cr	3

PARABATTERIES:
 These are a Bilitium power cell that are used to run many items and vehicles across the frontiers.  A 1 km range is equal to a 10 SEU charge of external power [weapons, equipment, etc.].
 Note #1: A Large PB in a small vehicle will give the vehicle more power. EX: a Large PB (4000 km) x by size # (Large is size #4) divided by Battery size usually used size # (Small is size #1) = New power rating (= 16,000 km)
 4000x4=16,000/1=16,000
 Note #2: A Small PB in a larger vehicle gives the vehicle less power.  Half the power each step up in size of vehicle.

CARBON COMBUSTION ENGINES:
 These are high maintenance engines like we are used to, hold over on some planets but on poorer ones these are the mainstay of technology, but one thing is they are easier to repair then all those electric circuitry needed for more advanced PB engines, A smaller engine in a vehicle other then what it was designed for cuts fuel in half, reduces speed to half per size decrease and takes up less space,  a larger engine in a smaller vehicle will add no fuel but will double speed per size up, and take up more space.  The major problem is that finding low tech perts on high tech worlds can be difficult.

FUEL TANKS:
 These are simply as stated, fuel tanks with lines included as well as pump.

TYPE		Capacity, Liters	COST	WT	HP
Motorcycle:		5	10	5	5
Car/Van:		20	50	20	20
Transport:	Small Medium Large Extra Large	30 40 50 60	100 150 200 250	40 60 80 100	30 40 50 60
Spare Tank:		10	40	20	15
Aircraft:	1 Tank per 6 Passengers	50	200	40	30
Jetcopter:	Small/Medium Large	50 100	200 400	40 60	30 60

JET ENGINES:
 These are what they seem, regular Jet engines, when an aircraft engine is used for a vehicle that requires multiple engines the designer can combine up to 3 into one housing at a 10% price increase. If  one is strapped to back of a ground vehicle {medium or larger} it will multiply speed of vehicle by 5 for a short duration [separate fuel tank needed] use your judgment for rulings.

TYPE	FUEL	DISTANCE	KG/MT	COST	HP
Glijet	20 Turns	50m/burn	2	50cr	10
Large Aircraft (1/20 Passengers)	Tank	10km/LT	2 MT	15,000cr	500
Small Aircraft/Jetcopter (1/6 Passengers)	Tank	30km/LT	1 MT	5000cr	250

Fuel Cost:
 This is the cost for 1 liter of the appropriate fuel for combustion/jet engines.

TYPE	COST
Gas Aviation	10cr 40cr

ELECTRICALS:
 These constitute all wires, electronic components [such as gauges, lights which are standard versions, etc.], and hardpoint hookups for radios, but not the said item that is extra.  To figure cost you take the  Base  cost and use the multiplier to find cost total. This is not used in determining HP, but is used for weight.

BASE COST: 1000cr                      WT: 1/4mt

VEHICLE SIZE	MULTIPLIER	HP
Small Medium Large Extra Large (Huge) Aircraft	x1 x2 x3 x4 x5	30 60 120 240 480

EXTRA EQUIPMENT:
  This refers to Life Support, Alarm system wiring [not the system itself], Computer Hookups and Weapon Hookups [power based, or remote firing].

EQUIPMENT	ADDED MODIFIER	ADDED HP
Life Support [per size] Alarm System Added Computer Hookup Weapon Hookup	+ (x2) + (x2) + (x3) + (x2)	30 x unit size 10 x system 10 each 10 each

MECHANICALS:
 This represents drive shafts, brakes [standard designs], etc.  Use Multiplier table above on the base cost below to get results.

BASE COST: 3000cr         WT:  1 MT                     HP: 100 mt

WINDOWS:
 This is self explanatory, but the description is given below under size of vehicle as COST/WT/HP [a - means  the polymer glass weighs next to nothing].

TYPE	VEHICLE SIZE
Front Shield Side [per window] Rear Armored	SMALL MEDIUM LARGE + 100/-/30 50/-/15 75/-/20 x2 200/.5kg/60 100/-/30 150/.3kg/45 x3 300/1kg/70 150/.3kg/35 200/.5kg/50 x4

MISC. PARTS:
 These items are placed in the vehicle, some will of course be needed others are purely optional.

TYPE	NOTE	HP	COST (cr)	WEIGHT (kg)
Seat D-Seat Bucket Seat Bench C-Bench Lights ENT-Set	Standard Type Deluxe Bucket * Standard Type non-Cushioned Cushioned Interior/Exterior Tape/CD/Radio	50 60 50 30 35 10 5	100 200 300 100 120 30 500	20 20 20 30 35 1 1

MOVEMENT STYLE:
 This sectioned represents the form of movement [wheels, tracks, etc.]. Below next to vehicle size in () is the multiplier to use with HP [items marked *] and WT.

TYPE	HP	VEHICLE SIZE [cost]	WT
		SMALL (1) MED (2) LARGE (3) X. LARGE (4)
Wheel, Rubber Wheel, Steel Track, Rubber * Track, Steel * Fan, Plastic * Fan, Steel * Jet [Water/Air] * ^ Water Hull *	20 30 50 70 30 50 75 40	30 40 60 80 50 70 80 70 60 80 120 140 80 100 160 140 90 110 180 200 160 180 240 210 120 140 240 260 200 220 350 280	20kg 40kg 50kg 70kg 30kg 50kg 50kg .25 MT

ACCESSORIES:
 These items can be added to vehicles, but these cost depend on size. Small(x1), Medium(x2), Large(x3), Extra Large(x4) are the modifiers for Cost, wt, and HP.

ITEM	COST	WT	HP
O2 Tanks (10hr) * Ballast Tank * Sensor Hardpoints ** Airlock Underwater Hardpoints	1000cr 1000cr 500cr 2000cr x20cr	.25 MT .25 MT 20kg/SIZE .25 MT x2	100 100 30/size 500 x2

SPEED TABLES:
 These tables are dependent on engine sizes.  Speed is in Meter/turn.

ENGINE SIZE	VEHICLE SIZE	ACCELERATION	DECELERATION	TOP SPEED	TURN SPEED
Small (1)	Small Medium Large Extra Large	80 60 40 20	40 40 30 15	250 175 125 100	70 60 50 25
Motorcycle (2)	Small Medium Large Extra Large	100 80 60 10	50 40 40 30	300 250 175 125	80 70 60 50
Medium (3)	Small Medium Large Extra Large	125 100 80 60	50 50 40 40	325 300 250 175	90 80 70 60
Large (4)	Small Medium Large Extra Large	150 125 100 80	50 50 50 40	350 325 300 250	100 90 80 70
Extra Large (5)	Small Medium Large Extra Large	200 150 125 100	50 50 50 50	375 350 325 300	100 100 90 80

DAMAGE REVISED TABLE: Roll 2d10 and add damage

DIE ROLL

EFFECT

2-3 4 5 6 7-8 9 10-11 12-13 14-15 16-17 18 19 20 21 22 23 24 25 26 27 28 29 30+

Body hit [take from armor first] Chassis hit Parabattery [take from armor first] Engine hit [take from armor first]{if no engine Parabattery hit} Fuel Tank [take from armor first]{if none then Body hit} Fuel ignites 10%/hit chance, vehicle explodes Jet Engine [take from armor first]{no engine then Body hit} Electrical [Take from armor then body first]{flying/hover vehicles lose control} Equipment [take from armor then body first, then random pick item] Mechanicals [Flying craft-forced landing, others -10% control] Window [choose randomly, left over damage hits passenger] Parts [choose randomly] Transport type [wheels,etc.]{armor hit first, then body 10%} Water craft parts [if none body hit] Turn speed -15 Acceleration -20 Top Speed -30 Steering Locked, Straight Steering Locked, Left 45 degrees Steering Locked, Right 45 degrees Spin Burning Roll Roll and Burn