In all the M cars I've owned I never mustered up the courage to buy an M5. I was there card in hand at BMW Leicester. Lovely example. 44k miles. Then the bombshell came "good news is sir we took it in PX for a regular customer and fitted a brand new engine as it had lost compression, while we was at it it's had a clutch and flywheel". He then produce an invoice for north of £20k!!!!
He said they will not make a loss as BMW picked up the tab!
It scared me to death and I backed out ended up with the M3.