What I'd like to see is a stationary lab / communication relay that processes samples that are brought to it by a variety of rovers that can be launched with the lab or in other missions.

It would be neat to see different companies, schools, or nations come up with variations on the rovers that only need to support the common interface of passing materials to the lab for analysis.

You could even drop more labs and build a network of them and expanding the range of your little rover nodes.

Once you have a decent rover design sorted out you can work on mass producing it and achieving economies of scale.