general problems of the 2006 Kia Motor Optima

I brought two new 2006. 5 kia Optima¿s (a red one and a black one) from our local dealer. Since I have had the cars, both of the vehicles have had electrical problems which started within a few months of the purchase. The tail lamps only last about 2-3 months before I have to replace the bulbs. First one side or the other will blow out, and then within weeks, the other side will go too. This has been happening with both cars ever since we bought the cars. When I call the dealer and ask about the problem, they just tell me i¿ve been buying cheep bulbs. I have had to replace the head lamps on both vehicles at the rate of about one every six-months on both vehicles. I have also had to replace what they called the ¿electronic throttle control� on both vehicles. Now there is a new problem with one of them. About 52,000 miles, I started having a problem with the parking lights. The parking lights would stay on when car was turned off and no matter what I do, the parking lights will not go off. The only way to keep the battery from going dead was to disconnect the negative battery terminal. About a month ago, we took the cars to our local kia dealer for an oil change. When we dropped them off for the service, I asked the representative (kathryn speakes), to also look into the parking light issue and explained the problem I had been having. To make a long story short, speakes said they forgot to look at the parking light issue, adding she would contact kia directly to investigate the problem and would call me when she has an answer, it has been a month . Today sahe told me it wii cost $400 to fix the lights problem. I find it hard to believe it is not a manufacture defect. This is not fair to the consumers who invest money into purchasing a new car. Please look into this matter as a matter of consumer rights and protection against manufactures known defects.