Favorite microphones for FX3 Run/Gun Interviews

Anyone have any favorite microphones to put onto the FX3 that work good in a run + gun situation? I don't have unlimited budget will spend the money on something if it's significantly better.

I'm working on a project soon where I'll be basically a fly on the wall at a band rehearsal. When they are performing I'll have all that mic'd up separately so I don't need to worry about capturing that on the FX3, but it's for when we are in a car going somewhere, at lunch, sitting around, etc.