Ciao Alika! No you do not necessarily need "è" in this sentence. The verb "essere" can often be omitted; in fact, the phrase you suggested sounds even more natural. Both phrases are fine, but a slight difference would be that in the textbook's sentence, they are stressing the second fact, about the car being very comfortable, whereas in your sentence you're just placing together two of the car's qualities. Vedi se ti torna (see if that makes sense)

We often join qualifiers using 'and'. My (not only mine) preferred way is using the following order: E` una macchina nuova e molto comoda. Other examples: Milano e` una citta` grande e anche antica. Livigno ha un clima freddo e secco. E` uno spettacolo lungo e anche noioso. Nino Frassica e` un comico bravo e di poche parole.