This is unclear as to where exactly this leak "is"!
Though I can't think of anywhere it could leak that would cost £600!
even if it was say the rear crankshaft oil seal that's around 4 hours lab'.
So your garage is hitting £150 an hour!
Where do you live?
central London?
Shop around for another garage that will explain where the leak is and give a more reasonable quote.
1/4drive
December 2014