This is my little attemt at making a vehicle creation rules set using the existing vehicles in SR4 and changing them into different crafts (Car to Zeppelin for example).

I apologize for the editing - it looks horrible

Select Existing Vehicle/Drone
Select the base hull of the vehicle you want to use (Arsenal, Unwired or SR4A)

Select Enviroment
Select and change the environment for the vehicle.
-Land (Standard Propulsion: Wheeled)
-Sea (Standard Propulsion: Ship Propeller)
-Air (Standard Propulsion: Fixed Wing)

One cannot change environment without its attributes changing – most noticeable speed, this is represented by the different rules changes below.

Select Propulsion Type
After the environment has been selected you may choose to change the propulsion already existing or stick with the one the vessel has. Usually a vehicle has standard propulsion of wheels, propellers or fixed wing and can then be upgraded into something more specialized.

Note, this is only for calculating speed, acceleration and handling – you do not suffer the drawbacks of sinking when having Amphibious Operation 2 on a drone just because it had water surround it for example, it is supposed to already be waterproof since it is a submersible in this case.

For example, an aircraft with the Lighter than Air modification as a standard upgrade may be changed to Improved Takeoff and Landing 2.

Land Propulsion
-Tracked Arsenal P143
-Hover Arsenal P136
-Walker Arsenal P144
-Rail (Limited to Rail) Arsenal P140

Air Propulsion
-Lighter than Air* Arsenal P137
-Improved Takeoff and Landing 1 Normal Speed, Arsenal P136
-Improved Takeoff and Landing 2 Normal Speed, Arsenal P136

*Exchanging already existing LTA to another form of air travel doubles speed and acceleration values.

Sea Propulsion
-Hydrofoil Upgrade Arsenal P136
-Submersible* Amphibious Operation II & Ballast Tanks I or 2, Arsenal P131

*Changing Submersible to regular seatravel changes speed values to X2
*Mini & Micro drones are limited to Ballast Tanks I.
Switching Enviroment
Switching environment affects the maximum speed of a vehicle while propulsion type changes might affect both acceleration and maximum speed.

Micro and Mini drones are not affected by environmental speed changes but are bound by propulsion changes – The only exception is the Ares Heimdall that follows the below rules with other vehicles.

Land to Air:Speed X2
Sea to Air:Speed X3
Sea to Land:Speed X2
Land to Sea:Speed /2
Air to Land:Speed /2
Air to Sea:Speed /3

Change Standard Upgrades
Additional upgrades are those that are needed for the vehicle to function in its new role at standard cost - but it is counted as standard equipment.

Example 1: Turning a Sikorsky Bell Micro Skimmer into a submersible
Changing a SB-Micro skimmer into a tiny drone submersible require several modifications that it should have to function properly.

First we change its environment into “Sea” making it a basic boat with propeller – Then we add the submersible option and replaces hovercraft with Amphibious operation II and Ballast Tanks 1.

We do not add this additional equipment to the total cost of the vessel as this is something added to a mass produced product – additional costs are always modifications added after purchase.

Example 2: Turning the GTS Tower into a submersible
We do exactly as the example above and change its environment to Sea and LTA to a Submersible – and add Ballast Tanks 2. We now split the speed by 3 [Air to Sea], lowering its base speed to 40, which is then split by another 2 by the Submersible option.

The GTS Tower would be a lightly armoured and very slow submersible that can launch a small fleet of submersible drones (or surface and launch air drones) while the Neptune can be a highly armoured anti vehicle vessel.

You could even change the Ares Heimdal into a submersible and have them function as fast torpedoes launched from the GTS Tower. The Ares Heimdall would have a speed of 500M per combat turn or 650 km/h under water.

Final Words
One can argue that the GTS Tower should be more costly since it has more upgrades since its (size wise) counterpart the Neptune – but the difference in attributes creates two different vehicles.

It is not a perfect system but it gives a lot more flexibility and a LOT more vehicles and drones.

After going through Arsenal drone listing I’ve compiled a list of what I deem to be security and military classed vehicles.

Classification and Device Rating
C: Civilan [Rating 3]
S: Security [Rating 4]
M: Military [Rating 5]

Base Price Changes
Civilian Drones: Cost X0,5
Security Drones: Cost X0,75 [Additional Costs if R or F]
Military Drones: Cost X1,0 [Additional Costs if R or F]

Drones not listed as used as a security measure, lacks a weapon mount or other drone weaponry or not having a [R] or [F] availability marking will be classed as “Civilian” and will be cheaper than their security or military counterparts.

Restricted & Forbidden Drone Price Changes
There is also an additional cost increase to vehicles with the [R] or [F] availability tag to represent that these things are damn hard to get a hold of and more expensive than your average household drone – Especially since those vehicles are very seldom built in large enough numbers to warrant a price tag slightly below a civilian vacuum cleaner…See below example – Mass produced garden tool VS high tech combat drone…

Horizon Leafman [Garden Maintenance] 4000Y
Steel Lynx [Heavy Combat Drone] 5000Y

R: X2 Cost*
F: X3 Cost**
*Mini & Microdrones are an exception to this rule.
**Ares Heimdall [Mini Drone] is NOT an exception to this rule.

Drones not listed below are considered Civilian
S: StoneBrook Smokecloud [Mostly used by Police and Military as distraction]
M: Ares Heimdall [It’s a freaking MISSILE – hardly civilian or security]
S: Ferret RPD-1X
M: Cyberspace Designs Dragonfly [Primary use, Anti Vehicle and Assassination]
S: Lonestar iBall [Primary use: Lonestar]
S: Ares Sentinel
S: Aztechnology Armadillo [EW platforms are usually not civilian]
S: Knight Errant P4
S: Modified GMC Chariot
S: Ford LEBD-1
S: GM-Nissan Doberman
M: Ares Auxilia Mk3
S: GTS Tower
M: Mcdonnel Douglas Nimrod
S: Saeder-Krupp Mk-17D Neptune
M: Steel Lynx [It’s a freaking miniature TANK]

Any drone with a weapon mount is a security vehicle.

Source: http://www.shadowrun4.com/resources/faq.shtml#8

Yes, true, but that leaves out several drones that should by default also be security vehicles regardless if they have a weapon mount - The Ares heimdall is for example a remotely controlled munition delivery system, something that should definitely be a military asset since corporate security seldom shoot missiles within their corporate owned enclaves.