Both boys have harnesses. It took awhile for them to get used to sitting strapped in but so far it's working out well and i feel better driving with them!
Gregory rides in his car crate he has since day one. on monday we got to the park before his friend and while waiting he couldnt understand you can sit in the front seat without the crate lol he looked at me like i was nuts
Guinness has a harness/seat belt that we bought at petsmart. Not really too fond of it and often gets tangled in it. But it keeps him from running all over the car