I would go to your local BMW dealer - they will 'rent' you a BMW for a Saturday or so.
Or even better go to a BMW drivertraining in the motordrome in Imola, Italy:
http://www.bmw.com/bmwe/services/drivertraining/
Regarding BMW on the Autobahn: Every BMW goes max. 250 Km/hour (155 miles/hour)! However, any good technician can release this 'stop' (at the Zuendverteiler) in a matter of seconds or minutes.