I have driven autos for 20years. I never leave the parking brake on on the flat but use it on hills or ferries. My last car prior to the RX was a Toyota LC5 land cruiser which I had for 7 years. I had no trouble with either the gear box or the brakes. I have always felt that leaving the parking brake on for long periods will cause 1) the cables to stretch & 2) the brakes to lock on, the same applies to my caravan, the parking brake is left in the off position once the legs are down, I have seen too may vans with locked brakes in the past.