I want to buy new oval speakers for the rear side of my car.But I'm having trouble figuring out which one to buy.The car came with the holes and ready cables for the speakers but without them. The hole for the speakers is 11.5cm X 9cm(4.5" x 3.5"). Since oval speakers are usually advertised in inches, I'm kinda confused which one to choose because there aren't any oval speakers in that size.
The car is a 1997 Nissan Serena GA16DE. Here is a really poor picture of the hole,sorry for that.