First, get a Sprint Booster - it transforms the car from feeling like a grand tourer into a motorised roller skate. Cheap and cheerful, too.

If you do decide to fit one, my advice is to forget the "use a magnet on the washer" ideas - I found this totally impossible. Instead, undo the two crosspoint screws holding the black under-dash cover nearest to the pedal box, wiggle the cover off, and then it is easy to gain access to the throttle sensor cable plug.