It seems like they changes the radios in 03 so i don't know if a radio from a newer truck (just the single CD, non-Bose style) would work in an 02. The non-bose Caddy & Danali's have the same radio right, nothing upgraded above the Chevy/GMC?

 

I don't think it will even fit without modifying the dash. Aren't the 99-02's only 1.5din?
03+ are double din.

 

it won't work. the 03+ stereos have to have a connection to the Class II data wire, otherwise it'll be locked.