Cars & Other Vehicles Who is the biggest auto dealer in the world? Who is the biggest auto dealer in the world? Longo Toyota What company has the most car dealerships? CarMax How many dealerships does staluppi own? Staluppi is the founder of the Atlantic Auto Group. Atlantic operates 25 dealerships in Long Island. And five dealerships in Nevada. Each year the group sells 50,000 new cars. Related Posts:Does CarMax give fair appraisals?Is it OK to buy from CarMax?Can I sell a PNO car to CarMax?Does CarMax have monthly payments?