Surely going to Moira through Dollingstown and Magheralin would be quicker? Although I do see the traffic backed up there in the mornings so your way is probably best!
I used to do the backroad all the way from the airport roundabout to the city, some fine roads up there, my old 1.2 used to take a raping on those roads, eventually takes you out at Sandyknowles roundabout. Had an awful scare there on enight, going round a corner and drove over a brick lying in the road, thought I was dead for a few seconds!
I see what you mean about petrol, i'm going through it at a scary rate but as i've only had the car a month the novelty hasn't worn off yet and I can never resist playing with the 1.2 corsas.
Will let you know if theres any interest for a meet and a run, need to get some more interest first. Might head into Bangor some Sunday night, theres always a gathering of motors up there.