Thanks to you all for great input. The Larini kit seems guite the ideal thing to me. A bit pricey but trail and erfor is usually not at all free either. Wonder how they install the wiring. As it is drive by wire in these cars, one could also make something into the wires from the accellerator pedal sensor aswell within the cockpit. But as you say, the ideal thing would be to make it open after a certain rpm level (where you usually nevef get any droning at load. The biturbos had a small vacuum pump to make the heater flaps work even when there was a constant boost instead of vacuum so not impossible to make a "stealth-system" where the car can be started quietly before the system gets vacuum from the engine. Now that I think of it, the Biturbos did have a vacuum booster accummulator aswell where the wiper mechanism is. It is indeed nice to not have to open the flaps manually every time you want full power for a short time.