A bit further away from Seattle, Walla Walla has a world wide reputation for wine and some pretty fine eats as well. That's a bit of a way outside the shortest routes to the rally, but going this way you could go to Redmond via Pendleton and John Day with some quite nice highways.
The best concentration of Oregon wineries is just a few miles south of Portland in the northend of the Willamette Valley. The region is mostly known for it's really excellent Pinot Noir, but other varietals are well worth sampling. I'd recommend stopping at Duck Pond Cellars on Highway 99 between Dundee and Newburg, then picking up a winery guide from them. Definitely find your way to Domaine Drouhin...it's a fab winery with a great hillside view location and their wines are over the top in quality.
Online I would recommend checking out www.washingtonwine.org for more info on the Evergreen State wine biz...be aware that there is a vast difference in climate in the eastside (dry) side of the our fair state, it's quite warm (okay...hot!) in the summer, so be prepared.
If you'd like more specific feedback on particular wines you're seeking, drop me a note and I'll try to fill in the gaps.
Cheers! Bill J
PS. +1 on Dave's comments above...there's a lot to see and ride in the Pacific NW.