Free=Outstanding! Modifications depend on your situation and potential BOL. Good all terrain tires would be the best/first place to invest. As others say tune up, maintenance, and belts/hoses as needed. If you want to be able to store/carry more, consider removing the rear seat.

rodney762 wrote:anyone suggest any modification?

I would do nothing that makes it unique form any other vehicle of the same model and type. If the SHTF and yours looks special it will be an instant target. In some ways the Kia Sportage is the perfect BOV as it does not raise any attention from people on either side of the law and it sips gas.

So make no modifications including tires, rims etc that would set it apart and take very god care of the gold mine you are being handed!