I don't remember when Emil Denemark moved from Ogden Avenue to 47th and Pulaski, but the family was evidently out of the business before they closed down. I believe the dealership was called Heritage Cadillac before they closed. I am somewhat surprised by the allegations that Mrs. Denemark was Al Capone's mother in law. As someone has rightfully pointed out, Al's wife was the former Mae Coughlin of Brooklyn, but simple math would also rule this out. Al Capone was born in 1899, and Emil Denemark was born in 1895, so if Jennie was in fact Al's mother in law, she would have to be at least 20 years older than her husband. Makes no sense.
As far as the supplier of mob cars, Denemark sold Frank Nitti the 1938 Fleetwood that was out at the Volo Car Museum for a while, but Joe Bergl, of Bergl Chevrolet at 54th Avenue and Cermak Road, was also a big supplier of cars for the hoodlum element. I have a friend, now 95, who grew up on Cicero, just north of Cermak Road, back in the 1920's and he confirmed a lot of this. His brothers worked at two Capone gambling joints, the Ship, just north of the CTA tracks on the east side of Cicero, where the currency exchange now is, and at the Cotton Club, right to the east of the former location of Bergl Chevrolet at the NE corner of 54th and Cermak.
Back to Denemark, even though he was a near west suburban resident, he is buried in the newer mausoleum at Bohemian National Cemetery at Pulaski & Foster.