[twobjshelbys]

You are experiencing compression braking and everything is working as expected - nothing is wrong with your car. You need to master the (difficult in a Cobra) technique of heel-toe downshifting. The maneuver is to, while braking, reach across to the accelerator and blip the throttle (to increase engine RPM) while simultaneously pressing the clutch and downshifting. Blip the throttle to increase RPM and then release the clutch. This gives the proper RPM matching of the engine to the new gear.

Search youtube for some videos.

It's a very difficult maneuver on a Cobra. The planar offset of the brake pedal to the accelerator is quite high making it harder to reach from one pedal to the other.

Edit: Ah, automatic transmission to boot. Not sure what the proper method would be, but it's the same problem.