Just wanted to post an update.
I've fixed the VCC bug (as said earlier in the thread, it was a simple fix... it just took me a year to find it ) and added Pay n Sprays. I probably won't bother adding Pay n Sprays to Stunt as vehicles are invulnerable and I'm out of memory in Stunt too. I also added the rest of the garages and cleaned up quite a bit of code.
EDIT: It seems that the motorcycle bug is engine-related, not MTA related. I tried getting on a motorcycle as a passenger in single player with no driver and the game crashed. Unfortunately I don't have enough free memory to try to make another workaround so this may go unfixed. The last workaround I tried had issues, anyway. I will test the workaround again and if it seems to work fine, then I'll just remove some of the garages in order to free up memory. I finally updated the first post, too. Updated changelog.
EDIT2:
The motorcycle fix is bugged. I couldn't get on as passenger after somebody else got on as driver (but they could after I got on as driver, weird... but whatever). The Cleaver & Machete seem to be partially synced as in another player can attack you and you see them attacking but they don't see you attacking (nor do they lose HP) so those don't work. Hammer is still VCC's melee weapon and the hammer is the only weapon in the tool shops.
Passenger code existed for the Pizza Boy which is only a one-person vehicle. I've removed that code in both DM and Stunt, and with the memory freed up in Stunt I was able to add Pay'n'Sprays. Woo. Otherwise, no changes.
Tested armor and it's all good, as are Pay'n'Sprays and interiors. I think it's done.