The vehicle is checked on a timer. If it's at zero value or less, or above a certain threshold in value, the vehicle is deleted. The upper threshold is going to be low, 4,000 nuyen (or less), so you can only get 400 nuyen worth vehicles here. Junkyard repair shop may also be tweaked the same way, so there's an upper limit to how valuable a vehicle they can work on.
If it's between those thresholds it's teleported to the junkyard instead. This is to force players to get the hyper-valuable vehicles immediately, while also making it interesting to have a bunch of junkers pop up in the junkyard. May also require adding a second decay timer when they get warped to the junkyard, so they don't build up.
Unowned/NPC flagged vehicles if above 0 value and below some arbitrary value (100k nuyen, or something), when fully repaired, swap their ownership to the repair person. This is to prevent people from getting super vehicles or other problematic things (although this will require building effort to support as it checks value) or vehicles that are set to negative/zero values (for some reason..).
Various issues with this concept:
Vehicles are currently a moneysink. There is nowhere to get vehicles other than purchasing them in stores.
Vehicles use a lot of special code that leads to higher overhead. This would be exacerbated if people started farming Americars and simply keeping them, using them en masse for storage or something equally ridiculous (although that last one is currently an issue anyhow, and probably would require adding a special 'save container' in vehicles to fix)
There are certain uber or strangely statted vehicles that do not seem special, but would be destabilizing to allow falling into player hands. Forklifts are the immediate example that come to mind, but I am certain there are others.
More overhead for builders going forwards as you have to be careful about future vehicles, or position hyperexpensive/powerful ones in places that are inaccessible for towing or use (on islands behind ferries/past bodyguards/in water, etc).
Basic concept outline:
The vehicle is checked on a timer. If it's at zero value or less, or above a certain threshold in value, the vehicle is deleted. The upper threshold is going to be low, 4,000 nuyen (or less), so you can only get 400 nuyen worth vehicles here. Junkyard repair shop may also be tweaked the same way, so there's an upper limit to how valuable a vehicle they can work on.
If it's between those thresholds it's teleported to the junkyard instead. This is to force players to get the hyper-valuable vehicles immediately, while also making it interesting to have a bunch of junkers pop up in the junkyard. May also require adding a second decay timer when they get warped to the junkyard, so they don't build up.
Unowned/NPC flagged vehicles if above 0 value and below some arbitrary value (100k nuyen, or something), when fully repaired, swap their ownership to the repair person. This is to prevent people from getting super vehicles or other problematic things (although this will require building effort to support as it checks value) or vehicles that are set to negative/zero values (for some reason..).
Various issues with this concept: