Cat Piss.

Damn that's a shity cat. I never hear of that as much as I do cats pissing in guitar cases and on musical equipment.

Cant you see the spray? it shines.

Buy new carpet, bleach n water area that may have gotten to the painted floor. Cloth or vinyl? Sorry to hear. My cats have never pissed in my mopars or in my garage or shop. Only time ove had one piss ...was on a dirty shirt on the floor.
I'd bill the neighbor or who's ever cat that belongs to.
Considering the OP statement, I would call it a pissy cat.
Ex brother in law used darts with a "feather" that he bent the pin over so it had a barb like a fish hook. A CO2 piston or rifle to fire them. Cat goes home with a dart attached it can not get out. Owner may need to take to a vet for removal like porcupine quills.