I don't subscribe to the view that there are loads of used GTs sat around 'in the back'. Before I ordered my new 4.7, I tried all the dealers bar two (Carrs (too far), Hurst (cars always overpriced and my 3200 came from them new which put some punters off with the V5 issue)) to get a used or deep discount new 4.2. Basically there is little stock out there. Some dealers have lots of punters looking for a three year old 4.2 and were prepared to put me 'on the list' and I have been offered some cars which never appeared on the Maserati used car locator as they went to someone on the list before they went public.
Bear in mind that prestige used cars sales were weak 2007-09 so there is not the volume of cars out there, hence high residuals. And if you want a new 4.2 for a big discount as the runt inthe litter, ring around as there are not any. I strongly encourage people to do the maths on a new, low spec, factory order, discounted car. You get the 4.7 and if you keep it 6-8 years as I intend to, the maths are ok versus messing about with two used GTs over that period. Plus you get your colour scheme which suited me as I did not want black or silver.