weirdfish

As is quite obvious I'm new to the scooby world, but not to cars, I've bought a completely standard early 2002 (51) plate wrx sport wagon, now I know these are referred to as "bugeye", but apart from that I know very little about the rest of it. Are they called anything else, are they similar in build to many other models, what parts etc fit that are made for other models.
I'm snowed in at the moment so I thought I would take some time and pick your brains.

Bristol98

Virtually any bits for the 2.0 turbo (from UK spec to STi) will be interchangeable. Changing turbos and the like will require a remap to get the best out of any changes and stop the engine possibly going bang!

One of the most common upgrades would be a VF34 or 5 turbo from an STi along with a decat exhaust and a remap, should get the wrx to around 320bhp...

bustaMOVEs

iTrader: (31)

Yep you can change quite a bit, can take power of upto 350hp without changing box

weirdfish

I was thinking about the exhaust as a starting point, I quite like the look of the standard twin tail pipes, where do most people go to get theirs done, will one of these places that make them to order whilst you wait be the way to go, or is there a supplier of this type of exhaust.
Also, how does cat removal affect the mot test.

bustaMOVEs

iTrader: (31)

Don't get a custom made exhaust they are not proven or tested, you can buy loads of exhausts off the shelf at loads of preformace places, check eBay etc and on here for second hand ones.
Unless you go decat it won't effect your mot just buy a sports cat downpipe if that bothers you or find a friendly mot garage, wink wink