 We purchased our Kia Optima 12/26/07, big mistake, not to long after we started having trouble.  Started out with the trunk opening up either going down the road or while it was parked.  Hesitation driving between 40 & 55, then the lifters started making noise.  Cruise control came on for no reason, & the list goes on. We took it to the dealer many times & they just told us that they couldn't duplicate the problem so nothing was wrong with it. We finally took it to a certified mechanic & found the problem in a couple of hours, that the service department where we bought the car didn't/wouldn't find. Resale value is in the dump.  It's not worth the money.