[SWHouston]

A few years back, we loved to go camping, and I would use a very long
1/4" Nylon Rope with snap hook, to limit my then (Old English SD) to the
near camp vicinity. Very inexpensive, and you can select the length, as
is required for the Site. The original piece was 50', and shortened/tied to
a tree/whatever, to accommodate the Site requirement.

When traveling/riding in the Car, I always use standard Harness', with
two dedicated Leash's (one for each dog) which are permanently fed
down through the separation/slit of the Back and Bottom of the seat
to it's metal under-frame. This allows a quick attachment to a pre
adjusted/lenthed Leash, allowing them to lay or stand and look out
the windows. BUT, not enough to let them be thrown into the back
of the front seat, if a sudden stop is required.