Mine's started doing exactly the same!!! A week ago it wouldn't start for about 20 secs, then did, and the other day it took about 5 mins, but today it was nearly 15 mins (I eventually fiddled with the fuses in the glovebox then it started) then I drove for 5 mins, stopped for 10 and it started up first time. But an hour later it took 30 secs again.

And I had someone in the car with me...