That pet barrier looks like an affordable solution.
For my little dog, I locked his leash to the seatbelt to keep him in his seat and told him STAY when I would lock him in. He could move around in his bedding, but the leash prevented him from pestering me while I drove. I had a rule with him, NO touching the driver while moving down the road.
Dollar tree sells 4 foot, $1 leashes that can be customized for this use.
Also it was a bonus if I had to get out to pump gas, he couldn't just leap out of the vehicle and take off. Once I got the gas flowing, I would then take him out for a walk around the station to let him do his pee-mail.
I have used this method to tie him to a chair too. We were on my RV patio and he was pestering my company, so I used a big D ring attached to his leash to attach him to a chair and told him to sit and stay. He realized he was attached to the chair and sat there during the visit without pestering everybody.
I've also used this method at outdoor restaurants. Used a D-ring type spring clip to attach his leash to my chair so he could sit under the table while we ate and couldn't run off at will. I could eat without holding the leash.
