Today I was able to get my new-to-me 99 frontier over to my pops house to actually start looking at things. The compression in all 4 cylinders is 160-165psi. The aftermarket radio wasn't working and after removing it, I realized why (gotta love other people wiring up radios). Installed a new, basic CD deck and door speakers, had to actually move the front door speaker wiring from one connector into the big one, since my stereo only had one connector on the back. Removed all of the old aftermarket wiring from the truck, the previous owner had major subwoofers and capacitors and stuff wired up behind the seat. The battery hold down was tangled up in the wiring, so I found some nuts for it and installed it back on the truck and then moved back inside to figure out the door locks/handle issues. Looks like I'm going to need a passenger door lock actuator assembly, and since the drivers lock cylinder is bad, I'll replace the lock cylinders in both doors, and rekey everything to match. I miss having an older vehicle, so the little stuff I did today was very refreshing. I'll post pictures of the truck tomorrow, I am not a fan of the wheels on it, but they have great tires on them, so I'll leave them be for now. What are some of the common issues on these trucks? I'll be getting it on a lift in the coming days to inspect the suspension and steering and such, but I wanted to make sure the top end was okay first.