Charles 
2007 Toyota RAV4 SUV Limited 4dr SUV (3.5L 6cyl 5A)
Bad Trans/Differential
 These SUVs develop an annoying differential whine at about 40 MPH and up.  There is a Service Bulletin #TSB- 0192-10 that addresses the problem.  Problem is it simply tries to cover up the problem by dampening the noise - hoping  the owner will go away.  Also the engine has to be pulled to simply replace a water pump.  The Service manual also states that the engine needs to be removed for spark plug replacement. It could really get expensive to own this vehicle for the long term.