Newer Cars!?

[C.A.R.]

But Tom you have trained to be a mechanic?

This is where your story falls flat on its' face, because it simply doesn't make sense. Mechanics don't complain about having to have a 'load of work done' because it's their time, not a garages.

If you really want to be a mechanic, you should be out there stripping the head off and prepping it for a recon head to come from eBay. Then I'm sure you could sell the knackered head on to a recon company (even on an exchange basis) as it's worth money to them.