1997 Ford Aspire oil burning smell in cabin

Your suspicions are logical and make sense. What's the question?

You have to look for the highest place you see oil on the engine. A lack of puddles on the ground where you park is not a good indicator of anything. Oil can leak from anywhere and end up on the ground, and it can leak from anywhere and pool in an area above the transmission or inside a cross member or frame rail, then blow out while you're driving. Typically you'll find the bottom of the floor is wet under the seat area.

Depending on how fast the oil is leaking, there's two ways to find an elusive cause. One is to add a small bottle of dark purple dye, then you search later with a black light. The dye will show up as a bright yellow stain that you can follow back to the source. For big leaks, you can use a smoke machine to inject a white, non-toxic smoke through the dip stick tube, then you watch where it sneaks out. That usually doesn't work well if the leak is from a pressurized passage that is full of oil. It will find its way out through a leaking valve cover gasket.