Thanks to EvilSTi for bringing this to our attention.
Apparantly Subura, in their pursuit to make the STi more "civil" to the general populous has replaced the metal motor mounts that come on the 04/05 STi's with one-piece, liquid filled items. There are already documented cases of folks snapping 1, 2, and 3 at once on a solid launch.
So, if you intend on some heavy duty launches in an 06 STi, be prepared for possible motor mount replacement.
Personally, I would just replace them now rather than worry about it everytime I got aggressive on the launch.
Here are some good alternatives (note..you have to buy the mounting plates along with the motor mount as the 06 mounts are one piece...plate and mount are all one unit:
STi Group N mounts and pitch mounts:
And here are the cusco engine mounts (same link as above). These are basically race ready mounts, which transmit a lot more noise and vibration into the cockpit.
There are other locations that sell these, but I figured these would probably be the most a few of the most traveled sites. I am not suggesting you buy from these sites. These are merely the first ones that appeared when I googled "sti motor moutns". If any vendors on this site read this and want me to place a link to their mounts above, please PM me and I'll do so.