Great way to market/retarget for sale - but think service as well. Most dealers start to market to service customers that haven't been in XX number of days. They offer discounts, rebates, gift cards, etc to bring the customer back in for service. And, usually send these via regular mail... blah!
But, you upload this list to Facebook to create a matched customer audience. Then created a promoted "offer" with the same discounts, rebates, gift cards, etc and target only this custom audience.
Of course the success of this is dependent on your dealership doing a good job of capturing emails AND inputting them into your CRM and/or DMS.