Yes, that's correct. Because the adjective "nice" modifies the noun "car", it would also be in the accusative case.

Of course, in English, we don't really have cases as such (in the sentence "the car overtakes another car", the first car is the subject and the second the direct object, yet the word remains exactly the same).

However, in Russian, you can see that the noun and adjective is modified:
We see a nice car
Мы видим хорошую машину

Because «хороший» modifies the noun «машину» (accusative case of «машина»), it changes to "agree" with the noun.

Similarly other modifiers change to agree with the noun they modify:
Моя машина очень дорога,
but
Я люблю мою машину

Also, as Russian does not use articles, you don't need to worry about these agreeing with the noun, but in languages that have both articles and cases (such as Greek), the article also agrees with the noun it modifies.