Can see torque convertor/flywheel from under the H3!!!

[solarflare]

My fiance and I have been looking at H3's and there is a 2008 white one, 46K, base model, I5, that we are really interested in purchasing. We had the dealer put it on the lift. Looks very clean...no rust, and everything is still black.
The only thing we noticed was that if you look up on the driver's side transmission housing, there is approx a 3-4" round hole. In that hole u can see the torque convertor/flywheel, etc. Isn't there supposed to be a plastic or metal plug in this hole????
Looks like it hasn't been on there for some time.....Also what can happen if this is missing? Does it do damage to the transmission, or should it be ok?