The newer Toyotas (Rav4 and Highlander) run what look to be hydraulic struts. Looks like these struts have power going to them, and I can only assume that there is some sort of pump inside or maybe even a screw or worm gear that allow for the opening and closing of the hatch. They aren't incredible large, so there is a possibility that they could fit in place of a standard gas strut. Older cars would use the standard gas struts and a third arm that would open and close the hatch.
The other tricky part would be handling how the rear latch activates. At least on the CX-5 there is already an electric release (via the rear switch/handle) which could be wired into. The only issue would be the logic and timing between releasing the rear lock and the struts to activate.
