I think mine are closer than that, but not by much. Maybe 2"-2.5" ? I'd have to measure it to be certain.
In some road tests there were diagrams showing the clearances under the engines for the S2 & TC and given the driveshaft inner height is set by the gearbox/engine assembly, it would be worth comparing those numbers as well. The same road test also gave numbers for the front/rear bumper heights which is also a handy reference point. I've posted the scan before but can't find it, so here it is again....
When I changed the suspension to the protech dampers I fitted the damper without spring and with the car on axle stands I jacked the wheel through a complete full droop to "driveshaft hitting the chassis" range to see if the bump stops were in the right places. To hit the chassis with the driveshaft you've almost fully compressed the damper (without bump stops), I can't recall the exact number but something like 0.5" of rubber would stop it touching.
Brian