TBM if you can get 3 hours of labour for £150 (including VAT) then you are doing very well.
Local MoT/general place in Wch is £80/hour +VAT
Independant MB place I go to is £110/hour + VAT
MB Franchise is now £150/hour +VAT
You owe yourself an extra beer and tip at your prices. I might be round when the wifes Mini needs some work doing
