I found this one on hunterk9.com.
It holds two. Sorry the photo disappeared.
This Deluxe Oversize Dog Booster Seat provides the ultimate ride for your pampered pet, holds 1-2 pets up to 25 lbs
Other dog car seats sit too low, or they are supported by straps that attach to the front of the basket, making it difficult for pets to see out or move around.
This patent-pending design supports the dog car seat from below, providing an unobstructed view and more comfortable ride for pets – with no clumsy straps to get in the their way.
Installs securely in one minute and even works in the back seat!
The Oversize Deluxe model features a padded & quilted construction , using microfiber and woven plaid fabrics to surround pets in luxury.
The dog car seat has a padded interior liner removes for washing so the seat stays clean and fresh.
A zippered, front storage pocket, and 2 (two) adjustable safety straps with swivel clasp are also included.
Exterior measures: 20"w x 16"d x 10"h
Interior measures: 18"w x 13"d x 7" high sides
Product Weighs: 4 lbs
Free Shipping via UPS Ground - shipping via USPS 2-3 day Priority Mail will incur shipping costs, UPS next day or 2nd day shipping rates available upon request - SHIPPING TO CANADA UPS GROUND is available email for quote