^^ yeah right, good luck with that - it's just like ebay mate, if the car's gone, it's gone. The best you'll be able to do is get him to send you a cheque for your out- of- pocket- expenses, but not including your time.
I would call him back and say something like 'a deposit means you should remove the car from sale, and you led me to believe that was the case, what would you do in my situation?' and let him answer you. If it's no better from him, tell him you'll speak to CAB and get back to him.
But to take him to court for £90 isn't worth it.....