does anyone know if the the part # 15204335 is a non Y91 or Y92 on the navigation

That part number you are referring to is for a LUX AMP compatible (Y91) INR (Integrated Navigation Radio...in otherwords, non-touchscreen). Non-lux (non Y91) INR's are very rare because 99% of INR's went into 2003 and 2004 Escalade's and Denali's (when navigation was not a common option). The remaining 1% went into TrailBlazers and Envoy's which used non-lux Bose amp's. So basically, if you want a non-lux navigation radio, you are going to need to go with a TNR (Touchscreen Navigation Radio). The TNR's came out in 2005 and became avalible in basically every GM SUV, so non-lux units are just as common as lux units. In case you are wondering, a NON-lux INR part number ends in '8421. Non-lux TNR part numbers end in '0706, '7827, '9827. LUX TNR's end in '7531 and '0099. The reason for different numbers is newer software revisions and minor updates. '9827 is the newest non-lux TNR and '0099 is the newest LUX TNR. Hope that helps!!

---Ben

thanks for the info, can you make the non-lux play dvd movies??