Before you spend any more money do a couple of things that are free. 1st, check your tire pressure. Most folks run it too low and don't check it enough. 2nd, slow down. Everyone in California likes to drive at 70-75+ mph and then complain about poor mileage. Me included. I use my cruise control all the time to keep my speeds more reasonable. As a side note, I am finding 65 mph in the middle lane is more relaxing than 70-75 in the fast lane and the time differnence on my 50 mile commute is negligable. Also be aware of how fast your are accelerating from light to light. 3rd, pack a lunch, $5-8 a day really adds up, it is much cheaper to make a sandwich or take some fruit. 4th, pay close attention to the price you pay for gas, I saw it today for 3.31 and 2.99 - guess where I buy mine?
I JUST picked up my new Tundra, traded a 92 Civic for it. The Civic was costing more in repairs than it was worth and I needed a truck. I have just over 100 miles on my ride and am just now hitting the 3/4 mark on the fuel gauge. I am driving really easy because I want to break the engine in right and I intend on keeping this vehicle and ultimately passing it on to my daughter.
Finally, every successful financial expert I have ever heard recommends against leasing a vehicle except in very specific situations and they say you should try to keep a car for at least ten years if you buy it new. Good luck.