My kayak-hauler is a 2009 Impreza. Love it.
I installed loops under the hood for bow tie-downs. Some people use the tow-eye instead (accessible behind a panel on the front bumper). For the stern tie-down, I used a loop of cord attached to the (inside) rear-hatch latch, until I added a lightweight hitch and now use that. I'm not sure what options are available on later model years.
I'm not a big fan of the factory rack, but that would probably work. I use a Yakima rack on mine (stronger, more options, easier to install and remove).
I often carry surf skis (21 feet long), so usually use a set of Goodboy Vee-bars attached to the rack bars ( http://goodboykayaks.com/). These give an full 8 foot spread, and works great for narrow performance kayaks: http://www.gregstamer.com/wordpress/wp-content/uploads/2012/07/P10401061.jpg. The downside is that it lifts the kayaks high enough you may need a steep-stool, if loading by yourself.
4-place Boat Trailer