WIP Problems swapping engines in the Hatchback

so to very briefly explain my situation here, i was bored out of my mind and tought on how to fill my time with something interesting... yea why not swap the V6 Engine from the Pessima, that nobody really cares about, and put it into the hatch, looks cool sounds cool... sounds easy hm...

so basically i've putten the engine in the car via Blender, after fixing etc everything to place and using the .dae ingame the car started to look weird, the tach is completely butchered (pics explain it a bit better) and the stock steering wheel turns under the car... again hard to explain, also the mirrors have no texture now and the windshield's permanently cracked... and the reflection of the carbody is kinda weird...
oh yea and the padles are weird

alright, so here's some pictures

 

did you make the v6 mesh separate from the actual covet's dae?

 

explain "separate" if you dont mind, hence i havnt worked with blender all that much

 

What he asks about is, if you select the engine, does the rest of the car get also selected, or just the engine (& vice-versa)?

 

Afaik when i selected any part on the car, the car wasnt selected completely so goes for the engine

 

what i mean is did he make the mesh for the v6 include the entirety of the covet or is it just the engine?