There's not much available . I need to find options for the same . My rifles are long suppressed at around 53 inches overall . Not much made past 50 outside and 40 something inside dimensions.
Here's one I did for a '17 Polaris General crew. Had a bunch of scrap metal I save for unknown future weld projects. I used some spare Kolpin rifle mounts from a quad project that I sold the quad years earlier.
These run lengthwise of the car and between the seats.