When you listen to music with only rear speakers in a car, you're basically listening to reflected sound. the human ear is much more sensitive to sound from the front than the back. And we have fixed lobes unlike dogs (for example) who can orient their ears to the direction of sound. This is why humans physically turn to face sound.
The rear shelf can have larger speakers. That's about the only advantage, so the norm is to use a pair of components up front, and a subwoofer in the back. This is the usual way to get the best possible sound quality.
Dude these are car speakers we are talking about . Have you ever seen speakers mounted on a car dashboard other then tweeters . My swift has no option to mount speakers facing front . Only available options are inside the four doors or behind . The door speakers will have very little space to get amazing sound quality . Do you like to place your speaker in a cupboard . At the rear because of the good boot space enclosure , it is better for a good sound reproduction .
First off, all enclosures in a car are leaky.
Second, oval speakers cannot correctly reproduce low frequencies without some compromise on higher ones. This is why all component/hi fidelity speakers are round. The basics do not change whether it's a home or a car.
Third, low frequency is not the only sound in a piece of music.
Fourth, you should look around for recommendations on good sound in a car. The best systems have pods built into the floor pointed directly at the driver, with a sub in the back.
Fifth, study a bit about psychoacoustics. The ear is not accustomed to hearing sound from behind us. The sound produced is unnatural.
Sixth, most good setups only use rear speakers as a 'fill' unless you're sitting in the back most of the time. And then too, the speakers should be ahead of you.
Seventh, each speaker is optimised for a specific range of enclosure volume. A 500 liter boot may not be best thing for sound reproduction.
Good Luck
