I did something similar for my driveway, using some thin plastic honeycomb-shaped pavers in which I put dirt and grass seed. Unfortunately, for car traffic, the

I did something similar for my driveway, using some thin plastic honeycomb-shaped pavers in which I put dirt and grass seed. Unfortunately, for car traffic, they still needed a strong support underneath: crushed rock stabilized with concrete. This is not very permeable for either water or roots, so the grass is limited to the little dirt inside those honeycombs. That dirt dries out very fast too, so I have to water a lot in the summer. It does look much better and is feels much cooler than pavement though.