I was playing last night and experienced a lot of audio glitches …after a hour or more of this …i noticed the car dynamics changed …my ariel nomad was no longer an insane mountain lion …it is now tamer then a kitten with a ball of twine …lacking forward momentum …but it’s insane now when reversing …i have tried some of my other cars …and it’s the same issue …i have even tried my other account and it’s the same with the cars in that account also …i can’t even win a simple drag race anymore …is anyone else having these issues ? is support and development team aware ? …i was having such a awesome experience playing this game …i started playing it with both of my xbox accounts to get double the enjoyment …but now …just a whole lot of disappointment …off to play one of my other games …not sure when i will be back …hope the team fixes the issues …super sad 
The sound glitches happen to me sometimes, they should be fixed in one of the last updates …
i had a wired expirence that i lost gas. the car was stottering for a moment didnt shifted and drove with the same speed. and then it goes well.
I know it doesent help you, but sometimes the game is doing wired stuff…
the only solution i can think of, that it is a connection problem with the internet or wlan.
(sry for my english)