Tbf IMHO all of the issues you've initially mentioned could have been avoided very easy by you. With buying any car you need to buy with ur eyes open and draw up a list prior to viewing of what you are expecting. Is spec, service history, owners, good tyres and brakes, long mot and check prev mot's online to get a feel for how the car has been looked after. Surely from the amount of 370z they have you can bastard together a good'un lol is kerb alloy or low tread ask them to swap it with another zed, won't cost them nothing but their time and doubt come end of month they'd let a sale go for something similar.David