I will try to check what the usage is when the lag occurs next time I play that map. Someone else on here posted about the same issue I am having and he even included a video. I get the same issue he does in the same spot. Link is down below. I don't play on low, usually high or ultra and again, I have no issues on any other maps.
https://www.youtube.com/watch?v=xwNkbKCcUa8
Anything regarding the skin for the Mustang? That is an even bigger concern since that glitch renders that skin unusable for me. Not only does the cockpit look terrible, but its also extremely distracting so I no longer use it and had paid BOINS for it.