We have a couple of teachers at our school who drive in pupils.
I think as a one-off it is not a big deal, although some people worry about insurance. I personally wouldn't put it down to doing business in my car though. I don't think it is great to ask someone to do you a favour when you don't really know them though.
If a parent were to ask me to drive in their daughter to get them out of a fix, I would probably do it but with the proviso that I am driving in at 7.30am, which would probably put them off. I wouldn't want to make a regular thing of it because of the responsibility. I may want to ask other parents to drive my daughter at some point.