Answer: Adding Modification's to a refurbished vehicle can increase a cars performance.

Detail : By adding more horse power with modifications such as super chargers said by

Detail ; Simple modifications such as high velocity exhaust systems can add an extra 1 to two horse power.

detail: Lastly adding the right performance parts such as sway bars, or high tension springs, can increase a cars handling performance.

 Research source; "5 Engine Modifications to Improve Performance." HowStuffWorks. 30 Aug. 2013 " .

conclusion:  A refurnished vehicle is a vehicle that is brought back to it original form or better, adding modifications can give a vehicle that extra leverage in order to be considered refurbished.