Has anyone found a way to lower the rider seat height on a Dragstar Classic?

Interesting question... Can I ask how come?

I don't think most people have had the need. It's pretty low as is and I've seen one comfortably ridden by a 4' 8" rider (controls had to be altered, though). Wearing New Rocks is an option apparently, but I wouldn't recommend it myself ;-)

You could drop the suspension a bit, perhaps swap out the monoshock for a slightly shorter one.

Failing that, your main option would be to get the seat padding resculpted with a deeper profile.

Just fit a seat like mine. (see the link in my sig)