The hole is very large, as there is a metal oil particle screen that can be pulled out as well, so they have to use a big-ass plug. I am guessing that they needed to make the engine as small as possible, so putting that screen down there with the plug was one way. The screen is also about 4 inches long.
Good thing my parents sold it recently. Cute car, but a pain to work on. Battery is under the passenger floorboard behind the carpet and a plastic cover, pain in the ass to get to when they need a jump.
Also, the automatic is not a true automatic: they call it an automatic-manual....you need to lift your foot off the gas if you want it to upshift, otherwise it will stay at 6000RPM the whole time. When you turn the key to start, there is a 2 second delay before the engine cranks over....highly irritating. Another safety feature from what the dealer said...