I did have an 'A' board years ago but it was either in the way in the rear of the van or in the way on the path.
So instead I spent more money on signwriting the van which has been money well spent.
It advertises whilst I'm sleeping, working and driving. I call it 'The Ice cream Van' because you didn't know you wanted one until the van turned up.
I pick up alot of business from neighbours to where I'm working as they read all the things on my van and it encourages them to ask.
Les