There is no reason why you couldn't use for DD. I don't personally. At the track, I just clip both belts in anyway.
I have a Rallye 3 installed, and it does a good job of keeping you bolted down, but is significantly much more difficult to install as the rear parcel shelf needs to come out. However, there is no question about the restraint angle of the tail straps as it goes straight back. Schroth recommended the Rallye 3 in lieu of seat back strength results being available for E90 seats.
Last edited by LiM3y; 02-14-2013 at 10:49 AM.