Not a bad idea, they would obviously be quite happy to pay at least €500 for the privilage, plus I could charge them an extra €1 each for every car that passes us on the A22, as that would be an added bonus to the day, having another box on wheels to look at...
Bro-in-law took pa-in-law to Le Mans last year as a 70th birthday present, posh hotel etc. I offered to to pay for a room for them at the Black Prince at Bexley, overlooking the A2 for a weekend. Much cheaper, and home in time for tea on Sunday.