I hope that nobody reading this has an unsupervised psilocybin experience in 2021. We are so close to being able to pay for a professionally supervised experience (and you can almost surely find one today if you look in the right circles and come with the right intentions) - these will enhance the moments of clarity and alleviate a lot of the confusion and darkness that are part of the territory with psychedelic experience.
I've benefitted greatly from a handful of psilocybin experiences in my life. The experiences were marked by long periods of profound terror and deep sadness, but I consider these to be powerful literalizations of anxieties, fears and attachments that helped me grapple with them in new ways. That said, I've glanced at scary thoughts that don't occur to me in daily life and came close to getting in trouble when I ran outside. Get a good babysitter - even better, track down a professional.
Here's a long list, along with a list of carseats that have been tested "3 across" in those cars. A minivan or SUV would undoubtedly be easier to load kids in and out of, of course.