Does anyone know where I would stand on the warranty front if I bought a car imported from Europe or Ireland?

Are you talking second hand? Depends on how old it was, and whether the original owners registered it with the UK.

Up to a year or so ago, a lot only had one year manufacturers warranty, so it would be expired now. New carrs now have 3 years. To get warranty work done in the UK, the original owner has to register the car when it arrives in the country with international motors (effectively Subaru UK). If they don't, IIRC the warranty is still valid, but you'd have to wait for a go-ahead from the country of origin before any work could be started.

it would be on a new vehicle, my dad is looking at swapping to a forester and is looking at picking one up from motor point

The foresters from motorpoint come from either cyprus or malta. They DO NOT have a Subaru warranty. Motorpoint give you a one year warranty of there own. The Forester XT (Turbo) is at 18,599 but then it'll cost you another £800.00 for the two years extra warranty and then another £560.00 for a cat 1 alarm. You may as well go to a Subaru dealer. You can get a new Forester XT for £20.000 with warranty and alarm and someone to take it back to if something goes wrong!