I have a 2004 Toyota Sienna LXE Limited with just over 270,000 miles. I was told I need the control arm bushings (I think lower) repaired/replaced. Toyota service said this was a two hour repair and around $700. Two other repair shops gave estimates over $1000 and requiring over 10 hours to repair. Why the huge difference? What does Toyota know the others don't? Does the engine and transmission really need to be removed then reinstalled? What does this repair really involve/require?