Power Steering Fluid Compatibility

Many vehicles will accept automatic transmission fluid in the power steering, but it is not worth detracting from the vehicle manufacturers recommendation. If you do use an alternative fluid without a recommendation for its use, you run the very real chance of destroying the internal rubbers/seals in the system. If you have an oil leak on your system then you should have it repaired, and use the correct fluid. A loss of power-assisted steering whilst driving could end up in a catastrophic accident.

In this pdf document put out by Toyota, it states:

Power steering fluid type: Automatic transmission fluid DEXRON II or III

Seeing as how DEXRON II and DEXRON III are used by GM in their vehicles (over the years ... now it's the newer versions), the Prestone product you are looking at should be just fine in there and should cause your vehicle no issues.

Although this doesn't directly answer the question, it should be mentioned that usually there is no such thing as a mechanic in a can (or bottle). If your power steering leaks, most likely you need to replace the leaking part. Your car is so recent that replacement parts are probably made. Prepare to spend about $1000 if it's the steering rack that failed.

Of course, because replacing the steering rack is so expensive, I do understand why people use these stop leak fluids. It may or may not work. For me, I had two steering rack leaks on my 1989 Opel Vectra, neither of which was fixed by the stop leak. Replacement parts were not being made, so the second steering rack was from the junkyard, and was as old as the first that started to leak, explaining why the second one started to leak as well.

Your car is so new that it shouldn't leak (the leakage is probably the reason why you need more fluid in the system). So, you had an uncommon early failure.