How do you design & build your own motorcycle or motor...
 

...scooter? I want to design something with lots of storage, wind protection, sporty looks with a 250-300cc engine. The Yamaha Versity would be perfect but they don't sell it in the US.

I would start with a Yamaha close to what you want. Hopefully you have some skill in repairing and tracing problems because you are going to need it. You would need to find some shops that actually build bikes so that you can get some scraps. Then, you will need to perform that search for those hard to find parts (shields) that you want to install on your bike. You may not find exactly what you are looking for, but use your imagination because you may have to fabricate or make minor modifications to get these parts to fit your bike. As far as sporty looks, it's all about fabrication and a great paint job. Find a paint shop that is opened to your ideals as far as giving you what you want.It's more work than one would care to put into it. But if it is your dream, don't be afraid to go after it. It certainly will take time, but most of the fun and delight is in building it from the corners of your mind. Even if it takes you 6 months to a year, it would be well worth it, because it will be one of a kind.Happy Hunting andGood Luck