I find it funny that Hyundai, a Korean car company, is using "Blue" to identify its most fuel-efficient cars. This move reminds me of the Volkswagen BlueMotion models and the AdBlue name for diesel-exhaust after-treatment fluids, both of which are very German. Identifying products as "blue" makes me think of a marine application, and the label could be confusing for consumers who are looking for products to help save the environment, which are more typically referred to as "green."
I spent an evening with the Elantra Blue and came away reasonably impressed by it. The Elantra itself doesn't feel significantly cheaper than other cars in this class, and it offers a better audio interface than the Honda Civic. I wasn't exactly blown away by the Elantra Blue, but that's not really the point of this car. If you want to own a new car that's inexpensive, safe, and gets good fuel economy the Elantra Blue fits the bill, but if you're looking for something small and exciting, there are a few better options.
At highway speeds there wasn't too much engine, tire, or wind noise, so I was able to use the $325 Bluetooth system, which has no integration with the vehicle's stereo. If you're looking for a fully integrated Bluetooth system, the Ford Focus is probably the best bet in this class, but it isn't available on the base model and is part of a more expensive option package. The Hyundai Bluetooth system might not be as capable as Ford's system, but it's still a useful solution for people who live in states that mandate hands-free cell-phone use in cars.