Once Starship becomes reliable enough, they should full it up to the brim with testing equipment to send to Mars.
Based on the strategy so far (which included putting a car in solar orbit) I think it's a safe bet that they will throw at least one starship out there with cheap or disposable cargo.
It would be interesting to see what people can think of for that.
I doubt many people will be too focused on sending more probes or rovers when manned missions are on the table. Robots are great but if you are already paying to put humans on the surface they are a lot more versatile.
I wonder if a mini-nuclear reactor with WPT would be feasible.
WPT = wireless power transfer?
I don't see that as being useful or feasible for this mission, but in order to refuel on Mars they will need a large and reliable power supply. Also humans are a lot safer if they have large reliable power supplies.
Nuclear is probably the best option, I'm afraid that given SpaceX's track record they may become impatient waiting for somebody to share their toys and try to do it with large solar arrays.
During the transfer that's no problem. By the time they launch we'll probably have good wafer thin solar-panels that can fold out to be very large. On the surface keeping something like that from being destroyed or disabled won't be easy. There is wind power but it isn't any more reliable than here on Earth.
I wouldn't cosign anyone's insurance if they would dare put the lives of men in the hands of a battery bank powered by wind.
TL;DR: They really should use nuclear reactors.