Hmmm. My experience is that there are plenty of 4 wheel rigs out there but very few people who can understand the results and know what to do with them. I'm involved with several forums and most people who have visited a 4 wheel rig have had a poor service due to the operators not understanding suspension geometry. ANyone can pres the buttons but if you don't know how to make the adjustments peoperly, and the order in which to make those adjustments, then the results will be poor.
Two places do stand out though.
Micheldever Tyres are widely reported to give good results.
SuperTyres near Chelmesford are also reported to give good results and know what they are doing. I can personally recomend them as they have completely cured my errant Vauxhall Omega, Started off my adjusting the rear toe. Then centered teh steering, adjusted teh front camber, and then finally adjusted the front tow. £70 all done and the car is transformed.
