hmm.. m more inclined to look at the mileage on that car and not the actual age.
at 121, 000 miles, a toyota is just fine. In fact I am surprised to hear so much going on with it.
Mine is over 6 years old, way more mileage than that and other then normal time things ( clutch plate 75,00 miles) i have had no issues. My car no too long ago, maybe even close to the 120,000 mile range.. I thought had problems as well. Took it in, not a thing
The last thing that happened was the oxygen sensor went out.
Replaced it myself .. very easy.
I too am not so sure that is necessary..
but, that is just my opinion ...