Are there any real differences between a Cup and the normal GTV V6 or is it cosmetic?
Purely cosmetic but as the Cups are Ltd editions they will always commend a premium and are a future classic for sure.
What is the handling like?
Very good as standard
How does the Q2 diff improve it?
Massively improves the grip and protects against the weak point which is the diff shattering.
Are there any other recommended modifications/improvements?
Yes lots too many to list search and you'll find
How does wheels affect the handling and what are the recommended sizes? Would spacers etc be needed? How does 16" compare with 17" and 18" etc?
It's no surprise that the bigger the wheel the harder the ride.
What are parts costs like?
Good to be honest and lots of GTVs are being broken on eBay at present so used parts are plenty.
What are servicing costs like?
Again very reasonable.
What is the recommended service schedule and cambelt change?
I think its three years now.
Any other expensive changes such as clutch or gearbox?
Clutch is circa £500, get the Q2 diff though as previously discussed.
How long will the V6 engine last 'on average' before a rebuild is needed?
No idea depends on how it's been driven & serviced. You'll get a lot of miles out of one though they are strong engines
Would there be many issues with keeping a GTV outside? E.g. frozen locks, leaks, rust etc?
Keep door rubbers and locks well lubricated. Components will deteriorate faster outside like spring pans rusting etc. preventative maintenance such as wax oiling wi solve these problems in the main.
Minor niggle, but how much of an issue are the water tanks?
Not sure what you're asking.
How often does the suspension need replacing?
When it's worn out ! They will last a while.
How thirsty is it in terms of oil (does it have a wet sump or dry?)
My two V6's I've had / got never used any oil.
How much of a pain are the electrics?
Not brilliant but not as bad as everyone thinks.
How expensive are replacement electric parts?
Tonnes of cheap used parts on eBay.
If air con is installed, how easily can it be removed?
Why would you want to remove it? The GTV are sweat boxes in the summer months.
How much for a full engine rebuild, and how much for a replacement/improved gearbox?
No idea, speak to Autolusso
And lastly are there any top spec cups about (either low mileage or completely overhauled), as the only V6 GTV I can find currently that seems to suit my brief is a stock V6 GTV that has a rebuilt engine and gearbox and a very clean engine bay?
The are short in supply but they come up fairly frequently. Clive is best placed to help you on this one.
P.s. It would of course have to be in red