Taken at 1/100th, getting a good success rate but background is to obvious so needed cropping out.
Taken at 1/60th, getting a little less success rate and background is still a problem (This is on the straight as the E-Type didn't handle the corners!).
Now down to 1/30th, getting some success and even bright background is acceptable without crop (although crop may improve the image).
Now down to 1/15 and obviously a step to far for my panning skills hand held (monopod / tripod may help), getting a very poor success rate but background is great.
Still at 1/15th but this time panning on the red car overtaking the black one - interesting (well I thought so).
The whole experience was a little Hare Raising