Same place on both sides. Top separated from trim above and just forward of rear wheels. Common issue or random. Odd as its pretty uniform in length on either side of the car.

 

I have a 2009 mcs vert and this happened to me and the dealer advised that it is due to a plastic part that holds the top in place. the parts broke and were replaced with steel replacement parts and no problem for a couple of years.
Don't know if your car is still under warranty or if these plastic parts have been recalled.
if you don't have it fixed you will probably get water in the car when it rains which will eventually rust or rot parts to the top mechanism.