Played with friends and yeah i noticed that,i had good time to drift and race on Sunset Peninsula also the spectator mode is great too(first time i used it).Yes, I noticed that many lights (headlights, taillights and track lighting) now have a twinkle and shimmer that they didn't have before. Try Sunset Peninsula at night with clear weather and you'll see.
So...not only do they bring Mustang month, but they bring the Dark Horse, Cobra R, '67 GT500 and Trans Am Mustang along with it. Yep, I'm definitely finding the time to play during this update. The Cobra R and GT500 make it worth it to me.