20 inch rims on 2005 cts rear passenger tire is rubbing on dips and medium bumps?

If the rear passenger tire on your 2005 Cadillac CTS is rubbing with 20-inch rims, it could be due to several factors, such as incorrect tire size, improper offset, or suspension issues. Larger rims can reduce the amount of sidewall flex, making the tires more susceptible to rubbing. Additionally, worn suspension components may not adequately absorb bumps, causing the tires to make contact with the wheel well. It's advisable to check the tire size, offset, and suspension condition, and consider consulting a professional for a thorough inspection.