Tint would be nice. I need that for my E36.
A 6-speed conversion would be great as well, just makes things more fun.
As for boosting your TL, I'd say no because of the drivetrain. Maybe if you tuned it well enough it would work, but if you set it up for a really peaky torque curve, you're just setting yourself up for disaster with a FWD car.
How much power are you putting down right now?