roll bar extension
 

I recently saw an ad for a roll bar extension - looks like a straight bar that attaches across the 2 behind-the-seat-bars. Anybody tried this setup? Is it a bolt-on? Drilling required? Does the top still work properly?
If it is easily installed and removed, it could be a nice track day addition. But somehow, from the physics side of things, if it's a quickie bolt-on does it really provide any true increase in roll protection?
My thoughts were (a) does it increase the height & protection (I'm tall, and with helmet even taller) and (b) it provides an attachment point for a 4 point harness should one want to go that route.
Open for comments...

Hey, you wouldn't by chance be healtoer on the boxster racing board would you? Just wondering because he posted a very similar question. If you are I posted up a response to your question and I will try to see what I can find out.

Maybe this will help (if you haven't seen it already):

http://www.renntech.org/forums/index.php?showtopic=2957&hl=#

http://www.renntech.org/forums/index.php?showtopic=2948&hl=#

thanks for the info - the renntech stuff was excellent. as far as I can tell from their website, the boxsters can do DE "as is", but if I go beyond DE then I suspect I'm looking at having to get the extension. the DE school is turn one at carolina motorsports park in SC. Will let you know how it all comes out.
other than the cost, the extension seems pretty straight forward according to the other threads - encouraging!
adam - I'm not heeltoer - but it is something I plan to enjoy refining next week :)

I think I would just get a used hard top if I was going to track my Boxster.