I realised yesterday I was on the wrong tyre pressures, should be 2.0 on fronts and 2.3 on rears not 2.2 on fronts and 2.5 on rears! so with this corrected as of yesterday all should be good.
Around town I /used to/ get 37-39MPG and on a motorway journey 41.1 MPG but then again around town I don't really like hanging around in traffic for too long whereas on the motorway I could not care less about going slow / fast or whatever
Not really much to look out for fault wise as not much goes wrong with the 2 litre 16v engine, just look for the usual visual stuff like stone chips and scratches and since you got a black one....swirls :O and those wheels...
If your rear seats fold then there have been people reporting that they hear a rattle coming from this area (on any e46 coupe though not just this model) over bumpy roads, this is usually the seat latch or the headrests as they can rattle in their seated position, just bung a small bit of tissue down there or something and the rattle stops.
Not had this issue on mine, however, some people on e46fanatics have corrected the rattle by stuffing tennis balls into the parcel shelf area from inside of the boot via the holes!
The 2 litre sounds good too above 3000rpm but not like it's being over worked or loud like other 4cyl cars and below this it is very quiet, even with the windows open all you hear is road noise when around town and an ambient hum.
You'll be perfectly fine keeping up with fast moving traffic as well.