That's very meta!
True, but most businesses (outside finance) have other ways to make money besides cajoling, skirting, finagling or ignoring laws (or the latinate "regulations," as you prefer).
"Regulation" (at least in the US) is a broader category, covering both "laws" passed by elected lawmakers and "rules" made by unelected public servants.
Secondly, Uber got big using exclusively licensed town cars. And vacation rentals have been around for centuries.
And both are primarily successful because they have executed at a very high level on a consistent basis.
That regulation is a decade or two behind the technology is unfortunate, but merely a side story.
I also spend a couple nights with family - they don't have any special insurance or taxes for me either. I don't really see any difference, I didn't annoy the neighbours in any case.
From the TOS:
"...we may charge you to reimburse the Carpool Driver for the costs associated with a Carpool Ride provided to you. [...] Reimbursements may include per mile charges at up to the prevailing IRS standard mileage rate, and other expenses like tolls and parking fees." (Emphasis mine)
"The issue first arose when NeXT proposed to distribute a modified GCC in two parts and let the user link them. Jobs asked me whether this was lawful. It seemed to me at the time that it was, following reasoning like what you are using; but since the result was very undesirable for free software, I said I would have to ask the lawyer.
"What the lawyer said surprised me; he said that judges would consider such schemes to be 'subterfuges' and would be very harsh toward them. He said a judge would ask whether it is 'really' one program, rather than how it is labeled.
"So I went back to Jobs and said we believed his plan was not allowed by the GPL."
Judges are not computers, and are generally capable of seeing through your clever plans.
If you're signing up to do this as a rider, well I don't think you should given the insurance problems and you not having any guarantee that someone will be held liable if they cause an accident.
Getting into a bad accident with an underinsured driver at fault is a life changing event.
Sounds like an opportunity to me.