Ask PayPal to verify the email is genuine?
Not being funny, but why would you take PayPal on a car being collected? You're setting yourself up for a fall, in my opinion. You should only take cash (get him to pay it in to verify genuine notes!!) or a cleared cheque.
If/when he gets the car and opens a dispute, then PayPal will likely refund him from your account as you have no proof of delivery (as far as I know, only a tracking number is accepted).
Anyhow, seems really iffy.