As Aerohead mentioned, the Kammback angle is way too steep.
My dad had one of these cars. I always tried to convince him to ditch the roof rack.
I would think about a full bellypan and wheel spoilers for you car. My dads car had a tendency to overheat, despite being stock, so watch those temperatures carefully when you block the grille !
You don't need a ScanGuage for you car. You can use a SuperMID.