Does he like driving?
Book some places on this
www.motorsportsensation.com
Make sure you take a place yourself

Its the DADDY of a day out. Truely mindblowing. Its only 50 mins from London by car if he needs convincing. Or 25 mins from Paddington. Or you can chopper in as well. Thats probably what I would do with unlimited Budget.
If you book up for it and are going to drive yourself let me know and I will book in too