Not necessarily true. But regardless of that, many mods created (BMW M5, G65 AMG, Grand Cherokee, etc.) have 6+ speeds in their transmission. It is just a feature that could be added for realism's sake. Plus I can't see why it would be a very difficult thing to add considering the manuals already support more than 5 speeds. And to name a few cars that are definitely not sports cars but have a 6 speed (though they haven't been created as mods for CCD): Honda Odyssey (6 speed), Honda Accord V6 (6 speed), Toyota RAV4 (6 speed), and the Jeep Cherokee (9 SPEED!). So as you can see, none of the above are designated sports cars, but they have more than 5 gears, some such as the Cherokee have well over 5.