ISO Mechanic to check potential purchase, Northern VA

I'm considering buying my first Prius, a 2012 c 4, with 51K miles. I'd like to have a mechanic check it out. I don't know any in the area where the car is located and have found some of the mechanics I contacted have not been too eager to look at it. Is this common among mechanics? Do most folks take their cars to their local mechanic or to a Toyota dealer for maintenance/repairs? Can anyone recommend someone they trust in Northern Virginia or nearby? Anyone have experience with having a Toyota dealer look over a car you're not buying from them?

A very secondary question -- where to find a cargo cover? This car is missing it and I can't seem to locate one anywhere on the internet.

 

Thanks so much!