duh

is there a car rental in downtown seattle near the piers

Gardyloo

Downtown, yes, all of them. If by "near the piers" you mean walkable from the cruise terminal (Pier 66, not Pier 30) then it's a qualified "yes," meaning 15 min. or so, uphill for part of the way.

duh

are these car rentals in hotels?

jimshep

There is a Hertz office on Pike Street across from the Convention Center and in the same block with the Cheesecake Factory. Avis has an office nearby.

dukhuntr

Which terminal? Lots of ships are going to Pier 30 now (new cruise terminal). Lot further walk than 66.