So, it is really easy to take a train or shuttle or something from the airport to downtown? I was going to rent a car 1-way (both ways) and go without in the middle since the Valet parking fees are so ridiculous. But I was just checking out 1-day, 1-way car rentals and they are ridiculously expensive (like $140 each way). Plus, it appears the car rental terminal in downtown Seattle is closed the day I would have to pick up my car to return (since it is Labor Day).
On the other hand, flights, even this short notice, are surprisingly cheap (about $200). It would still cost a bit more (as me and my son are going), especially factoring in how much a shuttle/train costs. But I just wanted to see if it was an easy thing to do before committing to the flight. I liked the flexibility of driving but may have to pass.