[RACER X #99]

Better figure about 6-10 track days, depending on how good you are at paying attention, before you can go it alone without an instructor riding with you. I know plenty of guys who think they don't need an instructor for more than one or two days. Those guys are still getting pulled out of the sand traps or they are in everybodys way. Anybody can drive 100-140 mph on a highway but it takes a little more experience to turn the corners at high speed.
Best investment you can make in your Cobra is some driving school instruction.

Lots of guys here have done it and they are the better drivers.