السّيارَةُ الْجميلُ لونُها – Is there a mistake?

No, there isn’t! If you thought that the word الْجَمِيل should be written with a ة, you might have misunderstood the meaning of the sentence. The second part of the sentence is a so called causative descrip­tion (نَعْت سَبَبِيّ). The sentence …السيارةُ الجميلُ لونُها means: The car whose col­our is[…]