What is better--BMW X3, Lexus RX350, or Infiniti FX45?

for your family needs, the lexus, infiniti or x5 will be the most suitable as they were made to carry five in comfort. if you already drive bmw, why not get another unless that is what you try to avoid. the x3 is too small for any family in my opinion, porsche is way overpriced, and infiniti rides stiffly. rx 350 is not as quiet as previous rx 330, but is still very popular amongst American families, as is the acura mdx.