-
Good advice from the Constable. I'd add to it check everything electronic works - all the windows, air con, cruise if it has it, radio, all the lights (good to have an assistant for this but something that reflects like a garage door or wall can work well too) etc. etc.
Start it from cold and get someone to check what comes out the exhaust. If you're on your own get the owner to start it. Once started just let it idle and listen to the engine note/revs and the exhaust. Generally listen when you test drive it, any noises/squeaks can be warning signs you can google later.
Go around each corner and press down your weight above each wheel - if it doesn't spring back up as you'd expect the suspension probably needs attention.
Much more subjective and difficult to measure but if it feels 'tight' when you drive it that's good, if it feels 'sloppy', not good...
This is awesome - thanks! Mate's actually got one up the road so was going to go take a (socially distant) look at it this afternoon, so should have something to compare it to.