According to Official Guinness Records,
The greatest number of times the rear of a car has been lifted clear of the ground (i.e. the rear wheels are not touching the ground) in one hour is 580 by Mark Anglesea (UK), at The Hind, Rotherham, South Yorkshire, UK, on 3 October 1998.The car was a Rover Mini Metro and weighed 810kg 1,785lb.
For a complete list of 1998 records, please visit 1998 Guinness Records in United Kingdom.