Due to my husband being an insurance claims adjuster for storms we travel TONS.... Airplane rides he has a Coach dog carrier that he is ok with but in cars we had a booster seat until I was meeting up with my dad one day and as soon as he saw him in the parking lot Guinness jumped snapping the harness out the window of the truck and ran to my dad (I meanwhile about died of a heart attack and went into a panic attack), we had a harness with a loop that went thru the seatbelt and clipped to the harness.. he broke that one too... so finally since the backseat of my truck is HUGE across, I have a Kodiak, and sometimes we would rent SUV's or Mini vans to go visit daddy I decided to get a shower rod that adjust and make it like a runner so he can play in the backseat but can not get off the seat.
Yea I know not everything has a 12lb sasquatch yorkie like me but that is what works for us