YOU SAID:

The car only goes so fast.

INTO JAPANESE

車はとても速く行くだけです。

BACK INTO ENGLISH

The car only goes very fast.

INTO JAPANESE

車はとても速く走るだけです。

BACK INTO ENGLISH

The car only runs very fast.

INTO JAPANESE

車は非常に速く走るだけです。

BACK INTO ENGLISH

The car only runs very fast.