Hello and welcome to Just answer,
The 2.2 engine has a canister type oil filter located near the rear of the engine around the place where the engine and trans meet, the leak may be originating here and running down the block/trans area check to see if the leak is coming from this location. This can be seen from under the hood.
There is an inspection cover between the engine and trans on the bottom near the starter, Can you remove this and look directly at the rear main seal to confrim the leak is here?
There could be an oil galley plug or a crack in the block or porosity issues with the casting. But unlikely.
The transmission is removed to replace the rear main seal and then the flywheel.
Important: Do not damage the outside diameter of the crankshaft or chamber with any tool.
Tighten Tighten the flywheel bolts to 53 N·m (39 lb ft) plus 25 degrees.
It has to be removed completely there is no room to "slide it back" to gain acess.
The engine will need to be supported with a engine supprting fixture as the trans holds up that side of the engine and the sub frame/engine cradle will be removed, it can't hang there on its mounts like a rear wheel drive. After the frame is installed back in a front wheel alignment check will need to be performed.
This is a Major repair! without the necessary tools and equipment it is almost impossible to do.
The inspection cover is around the starter and the installation procedure is posted below the words installation procedure,
You need to remove starter if there is no inspection cover, you need to make sure of leak before removing transmission.