Your article doesn't debunk it at all. It merely confirms that closing dealerships hurts Republican owners more than Democratic ones. Major fail on your part.
Do you have reading comprehension problems?
There is no demographic difference between the percentage of Republican dealerships that were closed, and the total percentage of Republican-owned dealerships.
If you have problems reading that last paragraph, let me put it simply.
You have 100 green jelly beans, and 10 red ones. Your friend asks you for 10 jelly beans.
If you give him 9 green jelly beans and 1 red one, are you giving him a fair selection of jelly beans?
Now replace Jelly beans with car dealerships, and red with republicans.
Now do you see?