Most off us change them at 10k
Hey thats an excellent idea with the ziploc, I used to use rags under the filter but the ziploc would be much better, it seems like a lot more work but when I change mine I pull the battery out of the way, my friend that works at the local G.M. dealership had a truck come in for a warranty repair on the a.c. and it turned out the guy changed his fuel filter and pried the a.c line that runs above the filter too far and broke it, so I figure that loosening the battery and pulling it back a little is alot better than spending $350 to fix the a.c. !I do it myself. I usually just start the filter getting loose and then put a ziploc bag over it and take it the rest of the way off. BTW, I take mine out the top and not through the fenderliner.