There are actually two Kia Optimas for 2006. It's not a split personality, just a matter of timing and conforming to U.S. regulations when it comes to naming. There is the 2006 Kia Optima, which is the outgoing first generation of the Sonata-based mid-size. Then there is the 2006.5 Kia Optima, which is pretty much the 2007 Optima, but since it came out mid-year, it can't earn the 2007 designation. The 2006.5 has a lot of improvements over the 2006 in the areas of standard features, drivetrain, and more legroom. Both versions of the Optima feature an LX and upscale EX trim with either a 2.4 I4 or a 2.7 V6 engine. The 2006 Optima hits 138-hp with the I4 and 170-hp with the V6. The 2006.5 ups the power to 161 and 185 respectively. The LX I4 comes standard with a 5-speed manual, and the EX I4 and both V6 trims come with an automatic (auto tran is optional on the LX I4). The 2006 Optima featured a 4-speed automatic, but 2006.5 offers a 5-speed Sport-shift automatic. The 2006.5 also has a retuned suspension for a more responsive ride. Confused? The 2006.5 Optima also has more legroom than the comparable Accord. Trunk space is up to nearly 15 cubic feet. In terms of features, there isn't much difference between the two designations. The LX is well equipped with power features and cruise control, while the EX adds a power driver's seat, 6-CD/MP3 player, and auto-dimming mirrors. Leather seats, a sunroof, and a power passenger seat are EX-only options. ABS, traction, and stability control are optional for the V6 engines only. A big safety upgrade in the 2006.5 is the addition of side curtain airbags. The previous 4-star crash ratings have been upgraded to 5-star, and the poor side impact ratings on the 2006 Optima have also been addressed by the new airbags in the 2006.5 Drivers agree that the 2006.5 Kia Optima is the way to go, and the improved I4 engine is much sportier than the V6, which is underpowered in the mid-size segment. Other high points include Kia's warranty, the affordability, roomy interior, and long list of standard features. Negatives include low gas mileage and uncomfortable seats.