popovm

Ah, yeah, so for whatever reason, BMW decided to do the opposite setup in the e21. In 2002s, the contact ring is mounted to the steering column surround and the contact plunger thingy is in the steering wheel. In later cars, where your steering wheel came from, the contact ring is on the wheel and the plunger is on the column. Check out what @John76 (one of the electrical wizards here) did to adapt an e21 wheel to work with the 2002 contact ring. 
 

Yeah, cool stuff. I've been following them on Instagram for a while and have seen folks get good results. Someone else here referenced them recently, but I can't recall if they were just prepping to send over an order or they had already used them.

A bad trunk seal will allow fumes to be sucked into the cabin. Lots of threads on it.  I smelled like exhaust after driving my car for 15 minutes, especially with the windows open, ironically, since it creates more negative pressure in the cabin. I used house weatherstripping attached to the trunk lid to test out whether it was the trunk seal or not.
 
I also replaced the center hood seal that runs horizontally and attaches to the hood towards the back near-ish the windshield. Mine was super crusty. I also bought the side seals but haven’t installed those yet (best prices I found were at Walloth and Nesch) I put pieces of duct tape to make up the gap between the old crusty sode seals and the hood. Again, told myself this was “temporary” just to test out the hood and trunk seal but it honestly will be there for a while as I sort out mechanicals. The smell pretty much gone now. Side note, fumes are nothing to mess with. As much as I’d rather be buying sway bars and fancy steering wheels instead of seals, your health is really important and those fumes are toxic. It’s worth spending the time and/or money to fix it. 
 
You may also have a rich condition or a timing issue causing incomplete burn of the gas but that’s a different problem. 

That's what I was hoping you would say! If you still have the turbo itch, buy a regular 2002 and slap on EFI and a turbo. You could probably do that for cheaper than putting a turbo on your Tii if you consider the cost of the parts + the valuation hit you would get on your Tii, especially if you go with a square tail. Or, buy a 335i.