Dog Training Supply

My friend is having difficulty with her two large labs when she drives, because she has a small car so they can only go into the back seat but despite their size they are still convinced that they can fit between the front seats and get up front. this is pretty dangerous for my friend while she’s driving, so she can never take them anywhere by herself, like the vet or out to a dog park or anything.

her birthday’s coming up, and i want to get her something useful, so i was wondering, in this situation, which would work better to keep the dogs safely in the backseat: attaching both of the dogs to seat belt harnesses, or having one of those “backseat pet barriers” that just puts a wall between the front and backseat. For anyone that has had either of them, please help me out and if you have a brand you like, that would be useful too.

Thanks!