Get the battery out it if you can and check for rust, then do it again, repeat untill happy.

Whip the boost pipe off if you can and see if the turbo is letting too much oil out, is the shaft wobbly?

check the boot floor and spare wheel well.

Are you getting everything with the car that was specified in the sale ad? the guy might have whipped some fancy bits off to sell seperate.

No matter what the seller says, take it for a setup, if you have the cash change the timing belt regardless.

And start it from cold.

Good luck dude!