Originally Posted by
scottishpoet
There is a highway. There is one service station en route, at cobham. Free parking for 3 hours
https://extraservices.co.uk/facilities/parking/
By the time you pay for the hire car and the parking you are paying a similar amount to the comfortable hotel to sleep in your car.
Indeed. Sleeping in a car is very much not a thing in the U.K. and the parking charges at a motorway service station are quite punchy for a overnight. Sleeping elsewhere is likely to result in the police waking you up or moving you on.
Like others, book a Gatwick hotel and then take the coach in the morning. London isn’t a 24 hour city so can’t really recommend partying or sitting in an all night dinner to pass the time.