J4 Bromley, J5 ClacketLaneServices, J6 Godstone. Since it is that far, you may find somebody nearer to Brighton. That said, more than happy to help if you wish to suffer the ordeal of driving for a whole hour in your new car.....!I'm near Brighton. Junction 5 is Sevenoaks I believe?
M25 isn't too bad though. It would be straight up the M23 to junction 7 and head towards Dartford. Shouldn't take me more than an hour on a good day. It would also give me some quality time with the car too.