Hi Queenie,
Apologies, Plod forgot to ask, something to do with his old age I think
You have a few options available of which I'll get the official details of and Pm you.
Youth Hostel in High Beech with a car park but sadly not secure.
Lea Valley Camp site in Sewardstone Road again has parking but no secure parking.
Holiday cottages (converted barn) in Sewardstone Road, has parking in front of cottage.
Travel Lodge in Sewardstone Road has car park but not secure (this is a 5 min walk from mine so yuo could park car in my garage if you want).
Debden House Camp Site in Debden.
These are all within 5-10 minutes by car from Waltham Abbey.
Regards
Michael