Ghost Start - Starter cranks after key is released (normal condition according to GM). My '06 M does this. My friend who sold me the car said this is the way he always starts the car - quick click to start position and release. I have been doing the same. However, lately when it is hot it will not crank long enough to start that way, and I have to hold the key in the start position.
Wondering if anyone else has experienced this and if maybe this is a sign the starter/solenoid is on the way out. I put in a new battery and checked all connections except at the starter. That's next and maybe pull it out for testing at the same time.