We are convinced that the Quran prescribes regular prayers above all to be aware of God and to remember his guidance. Words that can not be understood neither warn against the wrong path, nor show the right path which is, at the end, what the Quran aims to do.
In any case, we can not imagine that God wants us to merely admire the beauty of the sound of his lyrics five times a day. The Arabic in the Quran may be perfect and supreme in its meaning, but as long as the person doing the prayer has not mastered the Arabic language, his prayers in Arabic are imperfect. Moreover, we do not know a Quran verse which requires prayers to be done in Arabic.