For giggles, I went to get an insurance quote on a 2003-plate Jaguar XK8 (4.2 litre naturally-aspirated V8 producing 300 HP) and it was basically the same as what I'm currently paying for my Coupe, despite my Coupe being a much cheaper car (both when new and when I bought it), a much less powerful car, and (in most people's eyes) a much less desirable car.
I also found that if I bought that XK8, the road tax is EXACTLY THE FECKING SAME - £270 for the year, or £148.50 for 6 months.
I did the same for a 2003-plate Maserati 4200 Cambiocorsa (powered by a 4.2 litre naturally-aspirated Ferrari V8 producing 385 HP) and found that although the insurance premium is higher, it's not prohibitively higher.
The scary thing is that both of these cars are easily affordable - I could buy a good, well-looked-after example of either car for under £8,000. That's right - V8 performance cars for Vauxhall Corsa shopping trolley money.
I wouldn't buy the Maserati because I know the Ferrari engine would be horrendously expensive to maintain whenever it needed parts (I can hear the cash register "ching!" already

I love my Coupe but have always felt it could use an extra four cylinders - and considering the running costs (other than the obvious one, which is fuel ...) wouldn't be that much worse for the Jag, I'm left wondering why I don't make the switch?
My Wife already voiced a concern that maybe the Jag would be less practical - less roomy - so if I did switch, I might go for a soft-top convertible rather than a hard-top Coupe - can't get much more roomy than infinite, can you

I think I'm going to call my current insurer and find out why exactly they're charging me such high premiums for the Coupe. It's robbery. I don't see any reason why a 160 HP 4cyl Peugeot costs about the same to insure as a 300 HP V8 Jaguar.
(I am thinking about this mostly because I think I may be changing to a different job with a higher salary - might not happen, and even if it does, I will still be keeping the Coupe for a while yet)