Looking @ Avis' Mobile Site, I get The Following BASE Rates for July 2-7 at SEA:

Chevrolet Aveo or similar - 528.99 USD
Chevrolet Cobalt or similar - 533.99 USD
Chevrolet Cruze or similar - 551.99 USD
Ford Fusion or similar - 563.99 USD
Chevrolet Impala or similar - 563.99 USD
Buick Lucerne or similar - 540.99 USD
Cadillac CTS or similar - 654.99 USD
Chevrolet Traverse or similar - 608.99 USD
Ford Escape or similar - 549.99 USD
GMC Yukon or similar - 774.99 USD
Chevrolet Equinox or similar - 558.99 USD
Chevrolet Suburban or similar - 905.99 USD