I have converted my PoliceB slot from the bike over to a state patrol charger. I went into vehicles.meta and copied everything for Police2 over to PoliceB in order to convert it from a bike to a car. Everything works great. The vehicle handles just as it should and everything. The only problem I'm having is I cannot change the level of the engine, brakes, transmission or anything in the trainer menu. I also have the wheel variety pack and I cannot change the wheels on this car. I do not have these issues with any other of my replace vehicles. I even have a slicktop version of the same vehicle from the same pack in Police4 slot. I am able to change everything on that car no prob. Can't figure out why PoliceB doesn't want to play ball. Anyone know how to fix this?

 

The kit available to change has to be changed through the carvariations file (which by default there is none for policeb) so you if didn't add a kit pack for the policeb slot you wont be able to modify it through the trainer

Ah. is that what the mod kit line is in Carvariations? I changed that line to massacro I think but it didnt fix the problem. Maybe I change the wrong Carvariations file.

1. You need to make sure you are changing the right carvariations entry not just any random entry you find
2.for the kit you should have it like this 
      <kits>
        <Item>0_default_modkit</Item>
      </kits>

Yep. I just went back into the Car variations in mods>update>update.rpf>data> and changed it to 01_defaultmodkit and it solved the problem. Lets gooo!