Tons of free parking in Scarsdale Train Station Commuter lot off of Garth Road. From Ardsley Road, head towards the Scarsdale train station. Right after you see the entrancy to the Bronx River and cross the bridge, make a right at the stoplight by the 7-11. Make a left (I think its the 2nd left) at Grayrock Road and then make your first left to access the commuter train parking. Read the signs closely as one half of the lot you need a permit but you do not need a permit for the other half. This is where I always park. I may see you there depending on what time my son's soccer game is.

You can also park in White Plains by the County Center, tons of parking but you have to pay.