I have intermittent starting problems with my 2008 Volvo V70. You would place the Key fab is place foot on brake hit starter button and nothing would happen. After several try it would start. This was an intermitting problem but progressively got worse. Dealer said it needed a new start module for $600. I decided to clean with contact cleaner and blow dry with compressed air. I did this several times and the problem has gone away. Its been about 7 days and no more problems so far.
Hope this saved me $600.00 and anyone else who may be experiencing the same issue.

 

I'm surprised that you didn't use Marvel's Mystery Oil.