>I find the car doesn't coast freely when the throttle is released suddenly. Looks like it brakes for a split second and then lets go again
well ... you are not the only one experiencing this phenomenon. 95% of my driving is on a rather loose and dusty surface where i didn't noticed it. But when i drove my buggy on tarmac i noticed it too. Not every time when i released the throttle but from time to time. This also comes in to play when you are jumping since this short braking phenomenon will let your nose dive as you release the throttle. I even made a small video where you can see this split second brake (my comments are in german though):
video clip. Look close at the front suspension.
gas loslassen = release throttle
bremsen = braking