07 vert. rear quarter panels retain water after a storm. on 2007 Ford Mustang

My 07 vert isretaining water in the rear quarter panels. you can hear the water when you turn a corner. interior of the car is dry. the water eventually drains out.this never happened the first 3 years that I owned the car. Why is it retaining water now?

1 answer
It could be that the drains are partially clogged in some way, causing very slow draining.