I am looking to purchase a Prius in the very near future and was looking for some opinions on whether it is worth it to buy a Prius 4 over a 3. The 3 I configured would have everything I want in the car. The 4 looks like it would cost an additional 3k and would provide a better sound system and auto on/off halogen lights that come standard. Am I missing anything else major that I should consider before picking one or the other. Prius 3 added options -Audio/Solar option -Added leather seats -Night vision mirror upgrade w/Homelink MSRP Total: 29,668.00 Prius 4 added options -Audio/Solar option MSRP Total: 32,930.00 Thanks!