Seat Covers Over Softex seats - wear on the softex material

We just picked up a Red 2013 Prius v - trim level 5 with the dark grey interior, last Saturday. This is the 2nd Prius in the family as we traded our mini-van on a used 2006 Prius in February for our son to drive to Minnesota. (we live in PA).

The Prius v has Softex seats and they have been very hot on my back when driving a long distance. (no, the heated seats were not turned on). We've already put over 400 miles on the car in the first week so there have been a couple of long trips driving in the Prius.

We are looking at putting velour seat covers (Gtcovers, exactseatcovers, or clazzios) over the Softex seats but were concerned about the wear on the Softex by the seat covers. Does anyone have a long term usage of seat covers over the Softex seats and the effect of the seat covers on Softex material ?