Well, what if i would buy a rs500.(i am actually considering this) export the car to a lhd country, don't like the rhd driving position. So i ditch the dashboard, steering rack, clutchcable, loom and a few more bits. Find sierra lhd parts. And voila, fairly straightforward work and very possible that there are more out there. But the chassis number will ofcourse sort things out.
But do you consider it a valid mod or an absolute nono?
And can 909's be reffered as rs500's? or as sporty sierra shell?