Re the speed brake:
A models never had them and with the A model only having an 800hp engine they probably weren't needed.
B+C models with the larger 1425hp engine do have speed brakes (and baggage compartments, the speed brake is before the baggage compartment, you just can't open the baggage compartment with the speed brake down as you would hit them together).
D models, being converted A models miss out on the speed brake. BUT some D models were converted B models so these may have had a speed brake.
I will look into Rogers DX10 issue.
Anthony,
That would be me...Let me try the shaders first, if it still does it I'll let you know.