Yes, bring a mechanic. Make up a check list before you go so you do not forget to check anything. It should include engine, powertrain, brakes, wheels, electrical, underchassis, interior and exterior checks. Check also for spare tire. And if you see rat or mice droppings in the engine bay then i suggest to stay away as the vehicle may already need serious electrical rewiring. Check the air filter and intake manifold as far in as you can in case mice have found their way inside there. And if you do see signs of mice living inside then as above stay away. It is not enough to just bounce the 4 corners to check the suspension, so do look under the vehicle!

As soon as you get it out of the bank's impound bring it to a garage for a complete engine flush, new oil, oil filter, fuel filter and air filter. I would even suggest you drop the oil pan, lift out the valve cover and empty the gas tank for complete thorough cleaning. Remember the previous owner may have had bad feelings towards the bank since their vehicle was repossesed and it is not farfetch that some of them might think of doing something to "get back". You know, like putting sugar in the gas tank or sand and even grinding compound in the oil with a perforated oil filter for added measure. A complete interior cleaning is also in order, dami na hanip sa loob nyan kasi more than 1 year nang nakatambay.