Oil has accumulated under car over a period of time, where can this be coming from?

Oil has accumulated under car over a period of time. Can this have anything to do with the rack n pinion? I think power steering fluid is leaking. Just trying to get some thoughts on what could be going on before I have Toyota take a look at it???

What kind of oil? They all look and feel slightly different.
Just put a piece of cardboard under the car while parked and see if you can identify it.

If you are losing power steering fluid, then it probably is the source of you accumulation. If you are not losing a measurable amount of fluids from your car, then the accumulation could just be from the road, especially if the accumulation is not very wet.

Have you checked all of the fluids (PS, motor oil, trans fluid, brake fluid, coolant) yet?
I would suggest that you do all of that as a first step.

Not only should it give some clues regarding what might be leaking, it will prevent you from driving the car with one or more of the fluids dangerously low.

Your owner’s manual will tell you where to check all the fluids and what you should be looking for to determine that they’re at appropriate levels.

If you put cardboard or paper under the engine, you can also find out where the oil leaks from. If you measure where the side and front of the car are relative to the spot, you can locate the failure. This, along with checking fluids weekly, can tell you what is leaking.

Just my 2 cents, with my early 90’s Toyota econobox, when I spot oil dripping on the driveway, it is usually caused by a leaky valve cover gasket. Sometimes it is just that the bolts holding the valve cover have jostled loose from engine vibration. (Don’t try to tighten these yourself unless you have the torque specs for your car and are familiar with how to use a torque wrench – overtightening can cause way more problems than you solve.)

There are lots of possibilities for oil-like-substances dripping on the driveway – some inexpensive to fix and some very expensive to fix – but the valve cover/gasket area is a good place to start looking.