Need some help. Ive used the search function but im still at a loss.

My S2 has developed an intermittent problem. Basically the car has been running fine but last week I had been driving for about 20 minutes and the car felt like it hesitated. When I was pulling up at traffic lights I put the car in neutral and kept the revs at about 2000rpm as I didn't want car to stall but then the car just died and the ignition lights came on.

I then bump started the car as I still has some momentum and i got another few yards before it cut out again.

I had to be towed home in the end as even when the car did start it would cut out sometimes immediately or sometimes a few minutes later.

The car is now starting fine and running again with no problems, done about 20 miles but after the local garage looked over it (with the car having no problem at the time) they are thinking its an ignition fault?

Anyone shed any light on the subject? As im just waiting for it to break down again so don't really want to go far in the car or make plans.