Br4d - to be honest I think they just want your money. I really don't think any additional training will make your chance of passing mod 2 any higher as you already ride a scooter and a car so you are experienced enough to go for it.
I'd disagree. The training is useful as it covers more than just how to ride the bike, it covers the stuff that the examiner will be looking for. Correct positioning, lifesavers, proper indication (and cancelling!), lane discipline etc.
Whilst somebody might be able to ride a scooter around it doesn't necessarily mean they can impress an examiner - they want to see everything done by the book so I'd recommend doing at least a couple of days training, not to learn the actual mechanics of riding but to learn the stuff that the examiner wants to see.