I was looking for a speed shop for my Subaru WRX to make it faster and corner. They guys at GRD in Naperville were excellent in customer service, price and worksmanship. They upgraded my turbos and other bolt on parts and my WRX just screams. They pricing is very competitive and I would highly recommend them for any imports or Audis upgrades. Location is at a prime location in Naperville where it is very easy to find and also a large shop. The shop and front desk was very clean (very important) and the owners and mechanics were very knowledgable regarding these cars. If there was a minor problem, they would fix it right away with no problems.