I've been to a few, and a few track days, back to a daily driver now though
The one of the right has a few modifications... free flow stainless exhaust, uprated ignition, port matched manifold nothing crazy though
I guess I'll add mine here, since I love it to bits
1993 Nissan Cefiro SE-4, imported by myself back in 2009, not many of these about and I'm not aware of another one in the UK.
Basically it's an R32 Skyline GTS4 in a different bodyshell, one that's much cheaper to insure and doesn't get any attention from the local chavs/police.
That was my next car after I'm bored of the 350z, however the running costs are ridiculous. People get fooled into thinking that they are cheap as you can pick them up for ~£35k, however servicing can set you back the best part of £1000 every 6000 miles... Also, I thought the 23mpg out of the zed was bad, but in the newer GTR's you will be lucky to break 18mpg .