"Peter likes to paint buses."

Translation: Péter szeret buszokat festeni.

[ErikAnderson3]

Word order question:
Is it flatly incorrect to answer this with Péter buszokat szeret festeni?
Does the object have to come between szeret and the infinitive verb?

[vvsey]

No, it is perfectly fine. Your version will emphasize the object "buszokat", that is all.