No mods here, beyond aftermarket replacement parts. The '06 Kia Sportage is the "senior citizen" of my mini-fleet. 185xxx miles, ice cold A/C, peeling clear on the hood, peeling leather on the steering wheel, loses a little coolant (smell it but never see it, been doing it for years). It was gifted to us as a teenager beater, when my parents, who bought it new, got such awful trade in offers that they decided it wasn't worth trading in.
Only real quirk is that an HVAC blower motor relay/resister got hot and melted the huge plastic connector to the wire harness. I replaced the resister and blower motor with new Hyundai/Kia parts and just crimped on spade connectors instead of trying to scrounge up the proper connector from a pick-n-pull. About once a year the wires to the resister melt and it quits working. I cut the wires back a smidge, crimp on new connectors and we're good-to-go for another year. I'm not going to waste a whole lot of time chasing an electrical gremlin like that if I can spend 15 minutes once a year doing a jack leg repair. Better yet, I still carry full coverage on it, so if it gets hot enough to start a proper fire and kill the car, so be it.