2000 Boxster 986 not starting intermittently

[ColtranePorsche]

Two days ago, my Boxster had been driving fine, perfectly normal operation, and then when I got in it wouldn't start.


All the dash lights would come on, and the starter motor was going, but the engine just would not fire up. I went back inside for about 20 minutes, called roadside assistance, came back out and what do you know, it started right up. This happened again yesterday, I went out, car drove perfectly normally, then when I went to get back in it wouldn't start. Waited about five minutes and it started again.

One thing that I've done in both these scenarios is put the roof down before starting the engine. I'm sure I've done this before with no adverse effect, but is there any possibility that doing this is sapping the battery or something?

It would be nice to get some opinions on what the problem could be from the 986 experts out there, as this could be an annoying one to diagnose with a mechanic if the fault doesn't present itself... At least maybe some quick fixes to get the car started if this problem keeps happening. Certainly need to get this sorted though as I can't have it making me late for work.

Cheers.