Re: Spider Problems Squek and lag!
get yourself down to amc in chelmsford, they sell the zender gear nob in their parts reception (the top one on the zender site with the carbon look and the finger grips) you will need to glue the gaiter leather to it though. They are reasonably priced too for most parts I've bought many a little bit here and there for next to nothing.
they can also run a full diagnostic on the vehicle which they did for mine when serviced, I had start up issues, they couldn't find a fault but reset the s/w to default on the ecu and no probs afer that.
Spider's do squeak!
You will notice a difference in drive type with tspark, you can't dump the clutch and floor it, the car is too heavy for that, you need plenty of revs and use the clutch to your advantage. change around 5.5 to 6.5 k to be back in the peak performance pull without revving the nuts off it. It takes getting used to but when you get it right, you'll wonder why you ever had a problem.
If you're still not happy after diag and driving style go organize a test drive in another spider and compare - make sure it;s not a jts though - drives differently - or a v6!
Welcome to owning a spider!