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On Monday, the actress, 50, and her 10-year-old son participated in the 74th annual Pacific Palisades parade in Los Angeles, where the duo cheered and waved to spectators from a bright red convertible.
For the celebratory event, Garner, who served as Grand Marshal for the parade, and Samuel wore matching t-shirts that read "Let Freedom Ring" in blue cursive lettering. The 13 Going on 30 star also sported a pair of black sunglasses while her son accesorized his look with a blue hat.
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Samuel recently got into a fender bender while visiting a luxury car rental dealership last week with Affleck and his fiancée Jennifer Lopez.
The actor's son joined the couple at 777 Exotics in Los Angeles where he let his preteen get into the driver's seat of a yellow Lamborghini.
RELATED VIDEO: Ben Affleck's Son Samuel, 10, Accidentally Backs a Lamborghini into a BMW at L.A. Dealership
While in the vehicle, Samuel hit a white BMW stationed behind him.
"Ben was at the dealership to test drive a new car.... Sam seemed very interested in the exotic cars. Ben let him get into the driver's seat of a very expensive Lamborghini, [and] the car ended up reversing into another parked car," a source told PEOPLE. "There seemed to be no damage to the cars though. You could tell that Ben very much regretted letting Sam get into the driver's seat. He seemed upset about it."
A representative for Affleck also told PEOPLE in a statement, "There was no damage. Everyone is okay."