... and the wind cried Mary
Scudrunner makes a good point, as does Lamonster in a previous post. 90% of adverse effects from crosswinds can be managed by ryding style. As Scud alludes to, when we feel ourselves being blown about by crosswinds, our natural reaction is to tighten up and bear down on the Spyder. Unfortunately, this just amplifies our bodies' response to what the Spyder is doing and the reaction becomes equal to or greater to the action of the wind. "Hold on loosely, but don't let go. If you hold on too tight now, you're gonna lose control," per 10cc. So loosening up on those grips, being an unnatural act, is something one has to train him/herself to do. You'll find that the wind isn't really moving the Spyder from side-to-side that much. Among all the other fables reported in this forum, no one has yet reported themselves blown off the road.
Mechanically and aerodynamically (I didn't catch whether your Spyder is an RT or an RS), the Spyder has a lot of mass up front, plus a closed fuselage as it were, where air can't pass through. The RT has the most pronounced effect with the larger forward area, huge instrument cowl and a big windscreen. Let us not forget the rear trunk area sticking up either. All these combine to cause a 'sail,' or air dam effect in crosswinds ... you can also feel the headwinds pushing back on the bike . The way I've mitigated this, mainly, is mod'ing my front suspension. I replaced my stock shocks with Elka Stage 1+'s, although ST1's are fine. I have 250 lb springs. Many others prefer 300lb springs (there are threads upon threads in this forum on the Elkas, adjustments, spring preferences, etc). This $700, was the BEST money I've spent on the Spyder in the 6300 miles I've had her and completely change the bike for the better on the road. Yeah, I feel the wind, but the Spyder doesn't tip or roll in it and that mitigates that 'sensation' you're reacting to. If you don't want to spend the money, you can crank your stock shocks up to max pre-load and it should help a little.
While not so much bang for the buck on the RT, I hear RS ryders, in addition to upgraded shocks, singing the praises of the Evoluzione sway bar. Finally, I hear the most recent DPS recall favors keeping one's line better in the wind. Otherwise, front tire psi: 20. Rear tire psi: 32.
~ Surfer :spyder: