Is it a good idea to go to a junkyard and hopefully find some nice alloy factory rims for cheap? Are there any incompatibility problems with putting factory rims from another car to a honda? Also what kind of cars should I be looking for that came with decent factory rims.

just make sure the bolt pattern is the same and it'll be alright.....also look for the same size unless u need to get new rubber anyways

also try and make sure that they are ROUND. i got some and they were jacked. you can't tell with the naked eye

yea just make sure they are somewhat balanced, check the bolt pattern, offset, etc..