I saw and first heard of these cars on NFS Hot Pursuit 2 back in the day and have always been interested in them. As I got older I was bummed to find out they were never sold in the US.
The Opel Speedster was built on the Lotus Elise (series 2) platform but had a bigger engine and was faster than its Elise counterpart. The Elise was super lightweight and the Speedster as well.
Vauxhall had its own version, the VX220. They made a version called the VXR220 which had more power (220hp) had bigger brakes and better suspension. Not too bad for a car that just barely weighs 2000lbs.
As for styling, the Speedster and VX220 look almost identical but I prefer the way the front grill looks of the VX220 more because I think the Vauxhall badge is cool as hell.
I loved Hot Pursuit 2, the first NFS and racing game I ever played.