Adjustment is made at the "splitter", where the e-brake cable splits to each side of the rear hubs just above the drive shaft and ahead of the diff. There is a bolt that can be tightened to engage the e-brake sooner. However, when I replaced my rear hub, I had to adjust this bolt several times. Too loose, and no e-brake. Too tight and the mechanism makes a clicking sound at the hub where the cable pivot point would hit on the lug bolts (see pics).

I've tried using the e-brake autocrossing, and it really doesn't do much to slow the car down. It is only designed to hold the parked car in place. Good Luck.
Mike