Lukas99GS

Hey guys, i recently test drove a black on black 04 Ls430 and loved it, would like to to purchase soon, I just have a few questions.
1. One of the parking sensors on the rear bumper was not black anymore it looked gray like the top had come off or something, are they easy to change and do you have to get them painted? Or can you get them in the oem color.
2. The car I was looking at had the smart access keys, but I've seen others without it? Was that like an option or?
3. The factory chrome wheels were peeling around the centers and didn't look great, I've always loved the gray/silver 5 spoke wheels, can't seem to find oem but have found tons of aftermarket replicas of them, can anyone say if they're good quality or which site, seller has a good deal. That would be the first thing I'd do to the car.
4. Has anyone had any problems with leather cleaner and the AC seats, I've always used the leatherique product on my GS with phenomenal results but I'd be afraid it could somehow clog up the holes that the air blows through.
5. And I know these are pretty bulletproof but is there anything specific I should look out for?