I took part cash from my Buyer, and a bank draft from the person my buyer sold his car to - so payment from 2 different people!!
I wouldn't have done this normally, but buyer came with a photocopy of his passport and Police ID card - I also met both guys I accepted payment from - furthermore, both were established members of this forum
If you take a bankers draft, take the buyer to the bank with you and pay it in and let the bank clear it - bankers drafts clear straight away, like a transfer, so by paying it in successfully you should be OK. Either that or get him to do a CHAPs transfer while you watch.