I've just bought a pattern crank shaft/position sensor for my Smart!! 
Dealer wanted £164+vat! Pattern Hella sensor was almost £45 delivered ..... 
Something in the water? Or rather the weather....
The galaxy died at some traffic lights yesterday, started straight back up. Nothing on the diagnostics scan suggests to me a crank position sensor failure brought on by high under bonnet temps.
Sadly with no other evidence to go on my only option is to fire the parts cannon at it
. Still, at £25+VAT it's not a massive ask on one of these.
The car actually died Friday evening after I'd dropped my grand daughter off at home. I left it outside her house Friday night, went to work in the ML. I tried starting it on the Sat evening but it wasn't having it. I called recovery yesterday who I arranged to meet at the car, I got there 1st, put the key in really just to take it out of gear but tried starting it ..... & away it went first time!
Code reader suggested it was the crank sensor ....

Sensors on line were all kinds of money from about £8

Anyway, the sensor is dead easy to get to if it dies again.