£27.50? for 4 wheel alignment? sounds far too cheap to me, are you sure thats not just for 2 wheel? I've never heard of 4 wheel for that price! I paid 80 squids for a laser 4 wheel alignment (which i still thought was expensive but now looks reasonable) but it took them a good 45 minutes. I suspect the cheaper price is for the old fashioned mirrors on a stick front end only, which having had it done (unbeknownst to me) on a car that need a 4 set up had it crabbing in a most disturbing fashion, scaring me half to death
....they use the backs to set the fronts...if the backs are bandy the fronts are made miles out!