My '87 was parked in a field for 10 years... ZERO mice. Shocking, really! The previous owner had these little anti-rodent scent bags hanging in it, I think they really helped.
Did have several others that got ate up by mice... a nice 93 Explorer, nests everwhere. Air filter box, heater plenum, behind the rear interior panels... didn't smell bad though, that was nice. My Bronco II was the worst. It sat in a barn for probably 15 years or more. I gutted the interior, cleaned everything, bleached the floors and side walls, and put in new carpet... still smelled like piss. The 85 Ranger I'm working on now had a big nest on top of the engine and I'm sure I'll find more.
New cars are weird, I expect mice in old ones, but you'd think something driven regularly would be no problem... my mom had mice in her Kia constantly, one of my friends had mice in his Kia all the time too. The dealer said they see it all the time, they get into the dash and eat stuff. Why Kia, who knows.