And in my humble opinion, the term rice is not so much derogatory as it is negative. There is a subtle yet important distinction between the two interpretations. If I consider a car to be too much rice, it's kind of like saying, for example, the water is too cold. Yes, like most words, the listener's/reader's interpretation varies. However, I still like to use the term rice because most (car) people have an instant understanding of what I mean when I use it. It is a good descriptive word that is not, of course, absolute, but rather a matter of degree.
I hope I made some sense...