Seattle Recommendations for Shuttles that Provide Car Seats?

Our family (6 adults and a 3 1/2 year old) is on a Princess cruise departing from Seattle this summer. We are flying in together a day early and will need transportation from the airport to the Hampton Inn downtown (the construction is supposed to be done by mid May and our arrival is June 29th :)), from the hotel to the port the next morning, and from the port to the airport at the end of the cruise. Can anyone recommend a shuttle service that will provide a car seat?

Commercial vans like those run by Shuttle Express don't require child seats.

We used Shuttle Express private car service from SeaTac to Hampton, from Hampton to port, and they were very good. Would definitely use them, again. We opted not to do a shared shuttle as we didn’t want to have to waste time doing pickups and or drop offs at other hotels

However, the cost was cheaper. We paid about $25 per head private shuttle (town car)vs

A then $13 pp shared shuttle van.

I price shop using http://www.limos.com and have had very good luck with them. You can put a request for car seats and once you pick your provider then I usually contact them direct to confirm.

Thank you for your helpful suggestions!