Still don't know what's wrong with the car and if it will be able to get us up there.
What's it doing? I considered driving up to Seattle but then I realized that completely sucks and I have no business driving an American car in a place infamous for its constant daytime traffic jams. o.O
IMO... it's not much worse than Portland, if at all. You
can get royally hosed if you get caught out when it's snowing, but otherwise I've run into the same frequency of "Good Lord, why did you rubbernecking idiots have to block traffic for miles just to watch someone getting a ticket?" jams and "For Pete's sake, don't just keep widening the same road, create a viable alternative" jams in Portland. They may even be more common.
For all that the I-90 and I-520 bridges in Seattle are a travesty and 405 is badly overburdened, at least they're a straightforward route. In Portland, I can't count the number of times I've gotten choked up in some utterly nonsensical routing or rerouting that the city engineers came up with. I have to admit Ballard is comparable, but most of the rest of Seattle is either well-designed or well-marked.
They don't do a great job at it, but I get the feeling the Seattle city engineers are at least trying to fix problems despite their political and geographical limitations. In Portland, I get the feeling that either they're trying to fix traffic congestion by annoying people into never driving (not necessarily a bad idea), or some of their best meetings are inspired by a really good B.C. supplier of "refreshments".
Bringing it back to the point, the biggest traffic problem you'll probably run into if you drive for Sakuracon isn't traffic jams - it's finding parking, same as downtown Portland. Wrt that problem, I'd heartily recommend the Park-and-Rides.