|For the harness clip you can use a cut down leash or a
leash clip at the end of lightweight rope or webbing. Make it just long
enough to allow the pup to comfortably lie down in the seat. This must
attach to the puppy's harness. Never attach it to a collar.
For young puppies I put towels in the bottom of the crate. Once I know
the puppies are past car sickness I replace the towels with a pillow.
Now that you get the idea you can probably come up with something that
works as well and looks better. Be sure to share it with us!
Note: Unlike the makers of human car restraints I have no way of
knowing what the safety rating of this seat would be. I do not claim that it
will save your dog's life. I do believe that it keeps the dog much safer
than sitting on a seat with no restraint and it keeps the driver safer too.