AK Cars in London

I called AK cars to confirm, and they had a dispatcher awake at 1am who confirmed the price and location.

The driver was early. He showed up at 4:30am and waited outside while we checked out, and helped us load our heavy suitcases in the back of his small mini-van / large station wagon. He took a longer route to Paddington (but all the lights were synced and it was probably faster than the most direct route) -- but I didn't care because we had agreed to a flat rate anyway.

He dropped us off at the station, wrote out a receipt, and off we went.

AK Cars was so reasonably priced, and so responsive that I would definitely use them again!