Available now for the 2008-2009 G8 is our 3-1/2 aluminum shaft with CV . We have done extensive testing with stock rears and with our 9" kit and believe this to the the most cost effective trouble free drive shaft for the G8 available today. The shaft will come with our signature billet plates for each end so you done have to go in to the rear taking a chance on upsetting the crush collar (see below for billet plate VS changing to a Pinion yoke below) Our shaft comes with a 300m stub system mounted into a billet aluminum plate to ensure not only strength but lighter weight than the normal way of doing this type of end (look closely at the CV end, its not all steel) The shaft only weighs 20lbs and come with grade 12.9 hardware with back up lock nuts to ensure no loose bolts. We have been using this Billet aluminum style plate for over 10 years on thousands of 1000+Hp Supras, BMW's and many more without any bolt issues.
You will have to remove the heat shield from above center hanger mount to install a 3-1/2" shaft and there is a possibility of clearance issues with aftermarket exhaust, This is a general warning, we have several test shafts out and not one had an issue. I have listed this because not all exhaust systems have been tested. (We also offer a Carbon fiber shaft is made from 3-3/8 and not the 3-3/4 like other manufacturers)