There is free parking at the Val d'Europe Mall which is a very easy walk over to the RER A Train Station there. We always parked in the end of the lot near the Lidl grocery store. As its the closest to the train station. (The mall is HUUUUUUUGEEEEE)
We drove there and parked everyday when we took the train into Paris as we had no desire to attempt to drive into the city even though we had a rental for the full week there. I think officially the lot closes at Midnight- we did return after Midnight one night and there was still one gate open that we were able to exit. (but all the other gates were closed unlike the other nights when we returned a bit earlier)
The pin on this map was the one gate that was open so we could exit after Midnight. All the other gates were closed at that hour.
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