Thanks for the replies
I went and started the car, other than the engine fault coming up initially whilst driving, there's still no engine fault coming up but still has the minor petrol smell and the shaking at idle. Rather than shaking, I'd say it's a greater than normal vibration which disappears at high revs. There's no service messages either.
It's driveable so I could take it to local garage rather than wait for the OBD reader, there's a BMW garage down the road from me as well but at £100 just to book an appointment, no thanks!