Five years ago, the starter had failed on my son's 940 na, ~160K miles. Failure mode: would not start when warm unless you whacked it with a stick. This method was used for a month. Fixed with an ebay rebuilt Bosch and no core charge. I still have this to play with.

Recent events: Another son's 940 turbo starter failed when warm, ~180K miles. The stick trick did not work but allowing it to cool did. It's replacement, Advance Auto Bosch rebuilt, failed after several days. (Advance Auto, buy on-line with a discount coupon, pick up at the store which was in stock, and a lifetime warranty.) Son said there was a delayed start when it did work. The stick trick did not work. Tested the starter with a direct connection from the battery to the solenoid. This only bypasses the neutral safety switch, and its wiring, but will not test the KPIII start position

Advance Auto counter person wanted to bench test their starter but my son said it would work because it fails only when hot. Another employee, more knowledge, agreed and it was replaced. The Bosch rebuilt replacement had a brand new solenoid.

The second starter, 3rd R&R for my son, 5th R&R for me, was done NASCAR speed. I took care of the dumb end the last two times thinking it was cleaner. Faster does not result in getting less smudged up though.

TOm

PS; When I say Bosch rebuilt there was some indications that there is a new aftermarket unit available.