I have an 07 Denali with UQA (Bose) and U42 (Rear DVD). I've been reading tons of post on this form and I'm guessing I need a 15940102, so when I go to search ebay, a few sellers are saying that 25846421 is the samething. Are they correct?

 

check with your local parts dept. We don't know part numbers here, we are techs and enthusists with some know-how.
I will say that part numbers change all the time so its likely that it will work

 

Just to update the forum. I purchased a nav radio 25846421 off Ebay for $400 from canada. I bought a GPS antenna from the dealership and had it program for $40 buck and everything works fine. Good luck!

 

Zmydust is your car equipped with Y91 option I have gotten a quote for GM dealership for a radio according to my VIN number which is 25846421 but then a guy tells me if i have the y91 option it wont fit how come? please let me know