Presumably this is a 1 Series?
'Sport' is essentially a base model with nicer seats. The M Sport adds proper sport suspension, body styling, better wheels and just generally looks and feels nicer.
Very few Sport models will have anything like an acceptable spec so you are much more likely to find a car to have been well equipped if it's an M Sport.
It's a 3 series. I've cocked up a bit then. I knew about the suspension but at the time I forgot :/
Ended up with a 62 plate with 40k on the clock for 11k
It's got a few extra but it's in great condition, 12 months warranty, 4 new tyres, full service + MOT It's come from nissan. Was taken in as a part-ex. So the warranty, service and MOT should be all good.
Just regretting not getting a M sport but everything was much more expensive and it's the wife car after all.
I must do about a thousand miles a year in her car. The rest of the time I'm in my van.