Since OP's problem seems to have been solved with little more than use of some WD40 by the dealer maybe the problem was just that the seat runners were too stiff for the motors to be able to move the seat fully back and just needed some lubrication? Somewhat confirmed by the fact that OP is only 5' 11" yet needed the seat "fully back" when other taller owners didn't need the seat that far back?

That's about spot on 

This thread needs a dentist, it’s like pulling teeth

21 hours ago, Ray34 said:

... for seat switch, no idea what he did 

 

3 hours ago, PetrolDave said:

Since OP's problem seems to have been solved with little more than use of some WD40 by the dealer maybe the problem was just that the seat runners were too stiff for the motors to be able to move the seat fully back and just needed some lubrication?

 

3 hours ago, Ray34 said:

That's about spot on 

 

At least with pulling teeth I can work out what's going on.

 

First the OP has no idea what the problem is, and then he does.    

 

An equally plausible theory could be the WD40 smell came from the mechanic's overalls whilst he sat in the car R'ingTFM  ?