Supposedly, there's a carve out in the law for taxis and rides for hire, which taxis and car services are quick to point out to you. Now, that's obviously up to you and your comfort zone. I'm not going to judge anybody, but my sister-in-law made it clear my nephew (3) was to ride in a car seat or a bus. So, we've did the bus.
On our way back, Mears didn't send the bus. We got a van and a couple had a child below 2. They had to hold the child and we were packed in like sardines.
So, good luck either way!