I liked the way last year you could build a bike and see how it looked before buying it. Since the 18's were released the site is messed up. I hope they plan on changing it to somewhat what it was. I look at it now and close it out in frustration.
I was able to do it Friday (and did for a couple models). Could have been an issue with their server, and it could have been a flash issue on your end. But, you can do it.
Edit: I just went and did it for a Heritage. So, if you cant, it MAY be on your end?
It might be Flash, but I was able to build a bike on my iPad which doesn't support Flash. Of course, the Harley servers may be sending a different page depending on the type of equipment you are browsing with.