SORRY, BEEN A WHILE, HOME ISSUES, HOPEFULLY GETTING ON WITH IT.. ANYWAYS...
20 000 mile service.. intermiediate (spelling hasnt got any better since been away.lol) service..
normally consists of: oil and filter, and pollen filter, full inspection and diagnostics. :)
longlife 2nd serivce will be similar, but more pricey. Longlife servicing in general, does cost more.
there is a difference in the service books, for either time and distance or longlife, but the registering/selling dealer should be a ble to tell you before you book in. but if its due its 20k, then it should of had a 10k..