Tom,
All the advice on here is sound. I have been to BHM twice now and so far driven the GDI Plus Four, a brand new 4/4 , a 2009 4/4 sport and an older plus Eight. Its hard to know what to go for but I did not like the GDI but it only had 97 miles on the clock and felt stiff and unbalanced, the 4/4 fell over almost at the first roundabout, a very unsettling experience indeed. The 09 Sigma was a delight but would need to have tb's I think to match my own car. The plus Eight, whilst needing a re-trim was a real suprise. It was shod with alloys and not heavy at all. I really liked it. Unfortunately all my tests were taken at the school run hour and I was only too aware of speed limits and that these were not my cars.If you could speak to Nick or Keith at BHM you would find them thoughtful and informative and well aware that this is a big decision.