Great cars. Awesome handling and good power make then a lot of fun to drive.
Tuning for the KV6 engine is a little on the limited side though, remap, decat, induction, although there are a few cheap diy engine conversion options though.
As for average MPG, depends how heavy your foot is
. Mine is heavy so cant give you a definitive answer on that!!
Fill the tank?...... Probably around 60 quid. I only do ?30 max to save weight!!
Look into whether the cam belts and water pump and stat have been done on ones that have done a bit of mileage. This is quite an expensive job, but apart from that the engines are damn good to go!!
I love mine to bits. Even when it plays up I still cant seriously think about selling it!
Hope that helps.