Extending seat rails?

[twoblacklines]

So being 6ft 8" and having an inseam of around 37" I am getting serious cramp in my A3 sportback.

I was looking today at cars with a lot of front length and a thread elsewhere showed up where you can buy extended seat rails. But Audi's are not on the list due to "demand" (ie they do them for the most popular cars).

I wondered if anyone has had this done (to any car) and your experiences? How much does it cost? Did they do a good job? Any experience of a crash with them?

I really want a mk1 audi tt 240 QS but whilst I fit in it (just) with the wider seats, I can barely use the clutch due to the seat not going back far enough...this could cure that.

I wouldn't mind a few more inches of leg room on my current car either.

thanks