That's what I use, one of those plastic bench seat carriers with the adjustable cup brackets. I'm running bucket seats and it just sits on the floor between the seats. I don't have any good pictures of it since I generally take it out if I'm taking pics or going somewhere it will be seen.
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It's very handy though. I also have plenty of ugly memories of MCRD having gone through in 1966. Glad to see I'm not the only jarhead in the mix.