It's a sticky one this and I deal with it every day. The car will be registered on HPI and if the buyer checks this, he will be wary of making a payment to you directly. This is because he runs the risk of you not paying the finance company, and then the car could be repossessed from him. If he makes the cheque payable to the finance company, they probably will not give clearance on it for 7 - 10 days and in this case if you hand the car over and the cheque bounces, you will be liable for the debt. A possible solution would be a bank/building society cheque but you might still find that the finance company will delay the clearance.If they do card transactions on line, and can advise if the card payment has cleared when it is given, he could pay the finance company - after you have authorised it with them - they can they advise you the funds have cleared and remove HPI interest, and you can then hand over the car knowing the funds have cleared.