Will a B-M short shifter void my warranty?

This is goint to be interesting now that Porsche sells the identical unit. Plus some dealers will install a B&M.

If you had a transmission problem Porsche would have to relate it to the B&M unit. Let's say an oil seal in the transmission goes bad and leaks oil, but you have a B&M. The B&M is unrelated to a bad seal. Porsche cannot simply void your transmission warranty because you have a B&M.

Our local group has been putting in the various brands of short shifts for years and no one has reported a problem with me.

The only thing I can think of is a guy on rennlist. He put a B&M himself and did not mark the shift cable locations, so he would pop out of gear. There is a special tool that I have and the dealers have to reset the shift cables. His dealer would not reset his cables because of the B&M. The tool only fits the stock shift lever, it will not fit the B&M lever. I tried to explain to him that was the reason but he did not seem to understand.

Go with the under car unit. There is almost no way a fairly smart mechanic could mess it up. Additionally it could be changed back so easily. Then there is really no risk involved.

Agreed. I've had the under car kit for around 6 months now and love it.