An alternative to the step-in harness is the Buddy Belt. It is more expensive, but very nice. For pics and color choices go to
www.buddy-belts.com. The best price I've found online is at
http://www.metropawlispetboutique.com/buddy_belt.html, which starts at $23.90. This is what I'm using for my own Yorkies when they're in their Lookout car seat.