01+ Aurora Temp Replacement

Your best bet would be to go to the parts department of your local GM dealership.  They have schematics with each and every teeny tiny part that's in an entire vehicle, and all have their own part numbers.  You might have to replace the entire temp unit thingy but most likely they sell just the cover for it.  I forgot what it looks like in that vehicle but it probably wouldn't be all that hard to do the swap yourself.  You can usually tell just by looking at their schematics.  I'm sure if you had the dealer do the labor for you they'd charge at least 20 or 30 bucks extra.