mercedes rg prima

It seems like you might be referring to a specific model or a concept related to Mercedes, but there’s no well-known model named "Mercedes RG Prima" as of my last update in October 2023. Mercedes-Benz has a wide range of vehicles from luxury sedans to performance cars and SUVs, as well as various concepts and electric models. If you meant something else or are looking for specific information about a particular Mercedes vehicle, please provide more details or clarify your question!