The 3 series is one of the best driving cars made. Repairs are VERY expensive, so be aware after your warranty expires. I learned the hard way. The Prius is just about perfect for mileage and everyday use. I could even fit my roadbike in the back of my 2009 Prius. What you will miss is how great your BMW handles as compared to a Prius. You will not notice it much at first, but overtime you will. You can't go wrong with a Toyota, especially a Prius. But be aware that the driving experience is far different than your BMW.