Conrad, you could also fit a sequential 'box to your lovely M3 and improve your lap times in the process but that isn't going to happen, right!
Gerald is absolutely right, with very old cars, change one thing, eg fit stickier tyres, and no only will the "improvement" be marginal at best but there can be an unplanned flow on effect such as wire spokes breaking.

Which brings us back to the topic, any safety or technology improvements to old cars not only have to be in keeping with the looks and spirit of the car but also actually increase the safety levels not detract from them..