Roughly every 3 or 4 weeks when i go to start my car i experience a whine noise as if something is stuck and the car does not turn over. After a couple of attemps it starts as normal. As i said it only happens once in a while..........Any ideas what it could be???

Also....

I have just fitted a Cat back Powerflow exhaust and K&N 57I INDUCTION and was wondering if anyone could give a rough Bhp gain guide i should be looking at?

cHEERS