Libertarianism isn’t a monolithic ideology, and opinions vary widely among libertarians. Furthermore, one who identifies as libertarian doesn’t inherently reject all utilitarian or communitarian values. Some may argue against seatbelt laws and drivers’ licenses on the basis of personal freedom and responsibility, while others might see the value in certain regulations that protect public safety. What unites libertarians is a belief in limiting government intervention to essential functions, but defining those ‘essential functions’ can differ greatly among individuals within the libertarian community. Libertarians often share common ground with leftists on social values, differing significantly from mainstream Republican politicians.

My followup question is usually what’s your opinion on seatbelt laws and drivers licenses.

Seatbelt laws would really only make sense if their purpose was to protect others from harm, but, as far as I've been able to think, this would only make sense in 2 scenarios:

1. You are in a car with other passengers. In a crash, one passenger not wearing a seatbelt could end up harming the other passengers in the vehicle simply by their limp body flying around, and impacting the other passengers. This does raise the point, however, that the other passengers could simply refuse to occupy the vehicle with that individual, or the driver could bar them from that vehicle. If all occupants are able to give consent to the situation, then there should be no issue under the law.
2. You have a child and you are neglecting that child's safety by not restraining them with a proper seatbelt.

As for driver's licenses, that's actually a rather complicated issue.

EDIT 1: As pointed out in this post, there is a third case that I hadn't originally considered in that, in a crash, one's limp, and unrestrained corpse could fly through the windshield and end up causing damage to someone else's property, or bodily harm to another.