I believe that setup is one of a kind for their EP car and was unable to find on the Mazdatrix site.

Regarding the Speedsource bar, I'm going to play around with my radiator and see if I can get it low enough and have the bar run over the return neck rather than try for below it by dropping the mounts from the original Speedsource design and cutting the hood. If I can drop the radiator enough I'm going to get the bar, of course I've got to make sure the car will still cool right.

Here's what the GCR says...

1. Any anti-roll bar(s), traction bar(s), panhard rod or watts linkage may be added or substituted, provided its/their installation serves no other purpose. The mounts for these devices may be welded or bolted to the structure of the vehicle. No suspension control mount or component shall be located in the trunk or driver/passenger compartment unless installed by the manufacturer as original equipment. Traction bars used to control axle rotation shall be one piece solid bar or tube. Heim rod ends may be fitted.

2. On those cars where an anti-roll bar also acts as a suspension locating device, the diameter of the bar may be changed. Bar attachment and pivot points on the chassis and control arms shall remain as stock, except as provided for in these Rules, Sections D.5.d.1., and 3.