I have no experience but can offer my thoughts...

If you can protect yourself, then I wouldnt hesitate- have a back up reservation that is cancellable; make this one cancellable; see what the car looks like when you get there; etc.

If the car is a POS, decline it and go to the next agency. If the car breaks down, park it and get another.

many years ago I rented a camper van in NZ. I was promised a new one, but when I arrived I got an older 4 speed with 380,000 km. I had no back up. Two days later in a rain storm with a leaking roof the night before I called the company in Christchurch and said "Come get it, Im going to rent a car and stay in motels". They put me on hold for 10 minutes, then said 'where will you be tomorrow AM? We will drive a new camper to you". The next AM at a camper park outside of Wanaka, a gentleman was shaving in the communal bathroom, I was brushing my teeth. He paused, said "Might you be Exec Plat?" I wasnt dumb enoguh to ask 'how did you guess?" )

The whole experience blew me away. Anecdotal I know, but at least then there was a different 'integrity' I felt in NZ on every level.