I'm getting a '03 DTS black/black with 45k miles for $20k.... I think thats a decent price from my research....

Is there a factory Nav option that i can buy and get installed? if so where can i purchase one?

Are there any other goodies i can get for my DTS such as an air intake or exhaust?

I actually like the stock chrome (or polished) wheels so i won't have to spend $ on that....

Thanks in advance!

Frank