I already saw on a few companies website that they offer to buy accessories or tuning kits for their products directly.
I think this is a very good thing to do to have an even better customer service.
Doing a shop myself I know that a shop can't always stock all the lines, kits, parts etc for all the products. And if you stock, you don't always sell all and then it is just worth nothing and you made a loss.
So for really special and small accessories in my opinion a webshop would add a great customer service.
e.g. http://www.flysurfer.de offers a webshop for accessories and I really like the idea.
So maybe that is an idea for the companies.
Would be good to hear comments from othe people as well.
Greets
Toby