I would like to know if a d400 fender is the same as a d300 fender. I am not concerned about marker lights and emblems just the structuring for replacement.
Gordo, the 300 fenders are different than all others. The lip detail is specific to 300's only. D400 and D500 fenders are the same. W500, D600 and larger are all the same.
D300 and D400 will interchange as far as bolting on goes, but they will look very different, unless you do both sides. The wheel opening height on a 400 fender is bigger than on a 300 fender.