No, it has to do with the updating process of the stats ingame of the car in question. I have raced a few cars now where I go to check if I have done the minimum 200 miles of breaking in immediately after racing and the mileage has not shown.
This ocurred two nights ago and I was a bit stumped so I decided to just do an oil change to go back to racing and after doing the change I proceeded back to my garage to find my car with the correct amount of mileage of over 240 miles. So it seems like a loading stall that needs some time/refreshing to get the correct measurement.