What size speakers are in a 1989 Oldsmobile regency?

The 1989 Oldsmobile Regency typically comes with 4-inch speakers in the front doors and 6x9-inch speakers in the rear package shelf. However, the exact speaker sizes can vary slightly depending on the specific trim level and options chosen at the time of purchase. For optimal sound quality, it’s advisable to check the vehicle's manual or consult with a car audio expert for suitable replacements.