Next time out I will be testing a purple aliminium screw kit for the D4.
There aren't that many screws you can change, but I have identified the following:
Slipper cap (center motor mount) x 4
Servo x 4
Front gearbox (short screws) x 2
Rear gearbox (short screws) x 2
Rear body mount x 1
Aerial mount x 1
Undertray x 1
If anyone is interested in one please contact me