Dberry, if you take the time to read Wikipedia article on the AMC Tarpon (which is the car the Marlin was based on) you will see that it wasn't a Cuda wannabe, since the Tarpon was developed in 1963, (the same time the Cuda was).
http://en.wikipedia.org/wiki/Rambler_Tarpon
Actually it's more like the 1966 Charger was a Marlin wannabe, since it too is an intermediate "Fastback" not "Hatchback" body style like the 1965 Marlin.
One of the reasons 65 and 66 Marlins proportions were all wrong, is because the President of AMC at the time (Roy Abernethy) insisted on it having the same rear head room as the normal sedan, so the roof line stayed flat until it went over the rear seating area then tumbled down too quickly. (This can be seen in the side profile photo of the Tarpon).
This styling mistake was alleviated on the 1967 Marlin, unfortunately that car was built on the even larger Ambassador chassis. Which was considered a luxury and not a performance car.
The rear view of only the Marlins roof " looks very much like the Crossfire coupe.IMO

 

Sorry, my ride in '67 was courtesy of the US Army and it was uglier than a Marlin. I have no idea of who made what or what it looked like. To be honest, I didn't like the looks of the 'Cuda either. That's why we have multiple choices.

 

Ok Dave, you win. But only because a "Big Gun" trumps a "Big Fish" any day.

 

I was out of ideas (and facts) so I cheated. Actually, my brother had a '65 Mustang fastback and I loved it, so anything that was competitive with it was on my bad list, including the 'Cuda, Marlin, etc. My tastes back in those days were all over the place but I've always preferred smaller in a personal vehicle. I'm sure the Marlin was a lot more comfortable, especially in the rear seats, but my teenaged brain didn't value that. My 60-something bones have a lot more appreciation for it now.

Happy Holidays,
Dave

 

You know, I can see a slight resemblance. Look closely at the C pillar and rear fender tops. Obviously not close in proportions, but I can see a similarity in the curve of the rear side windows and the flow of the roof line.

 

It's been a few years since I've driven my Marlin, but it always drove very smooth. It's a luxury classic alright. It just floats down the road quiet as can be. With power steering, disc brakes, the ride was very impressive for a '65 that's 40 years old. Also I thought the fully enclosed drive shaft was innovative. You literally can't see the drive line. It's sealed in a tube from tranny to rear end. Unique car, not my chevy flavor, but good enough to keep the last 8 years. I had a buyer who owned one in high school and wanted it bad, but his wallet was quite there yet. I'll sell it to a diehard AMC loyal one of these years or keep it for another 8 years.