Interestingly, that word order is also valid English, though it has a slightly different meaning than "I like red cars".

Example: "I like [my] soup warm".

"I like soup warm, but you can eat it cold and left over if you want."

"I like having soup warm"

"I like my cookies freshly baked"

"I like men muscular and toned"

"I like my women blonde, so you can go for the brunette"

"I like cars red" doesn't quite work as well but doesn't seem wrong. Add a little context and it seems more normal. "As a buyer of many sports cars, I like my cars red, even despite the speeding tickets I get".

Perhaps a linguist could explain how this phrasing works.

(That said, of course I advocate teaching her to speak fluently and to use that word order only when she intends its subtlety of meaning.)