Any idea how to make ac look like this?

http://www.racedepartment.com/media/videos/assetto-corsa-hypercar-duel-laferrari-vs-mclaren-p1-spa-circuit-cams-4k-uhd.8642/

I know this uploader uses post production on the videos, but I'm wondering if it's possible to achieve this 'photorealistic' colour palette. I have my graphics maxed, but can't quite get it looking as realistic as this video depicts. Any suggestions?

 

The video is choppy, probably drops below the 30fps it was recorded on at 4k.
Having motion blur on max helps to bring in extra smoothness to the footage and reduce the bitrate needed for encoding, which is a serious limitation with Youtube and any other free video hosting.
Although here it seems a frame blending might have been used instead, it shows on any still frames that they consist of several other frames. So at 30fps it looks smooth when played but garbage when paused if there is motion in the scene. I think Sony Vegas has frame blending enabled by default. So beware when editing, there may be things turned on by default that you may or may not want. Motion blur in AC is bugged and sometimes makes the camera shake a lot, even when a car is still, it's also very performance expensive.

The left, LaFerrari, looks unreal.
Right, P1, looks decent, any reasonable Yebis filter can do this, the trouble is most people record with the default filters from Kunos that are blown out in some scenes, too dark in other and have way too high contrast and saturation, making them look unreal. The color palette is pretty neutral, which is what you get by default. There is in both a noticeable amount of chromatic aberration which is something you mostly get with cheap crap lenses, but again it helps blur the edges of the image and reduce bitrate needed.

Either make your own Yebis filter or download some (Natural, Pitone, ...).
I made my own after trying some other that don't look real to me nor use all the features there are. Like Ambient Occlusion. Makes a huge difference for in car views but is noticeable in external views as well, gives more mid range contrast to background.

For me the "wow factor" of the video in question is the smoothness via motion blur and or frame blending while recorded at 4k. There is no other way to make a footage look better detail wise other than to record at high resolution and to get rid of thin lines popping in and out blurring it all does the rest. Obviously you need hell of a GPU to push any decent settings at 4k even for 30fps.
If I use my film preset I can barely do 30fps, 24fps is 100% save. That's with 280x and 1920x1200, extra 5ms spent in custom Yebis compared to when I turn the advanced features off, another extra 5ms spent in ReShade to add proper soft bloom, DOF, SMAA and slight color grading. Tuning and turning features on/off easily makes FPS go from 30 to 100fps. It's always a trade off. Most of the time high above my recording FPS but there are certain scenes and situations where AC drops FPS a lot so beware and test your minimum FPS with those. AC is unbalanced, unoptimized and easily varies FPS a lot between scenes.

Bottom line, don't use default Kunos presets as they are garbage and look like some over saturated, high contrast console game.