Reg Chand said he used to work on Airport Drive opposite Park n' Fly.
He said he and colleagues saw drivers doing donuts and skids, and racing each other, in what they believe were customers' cars.
Park n' Fly director Mohammed Alim rejected the claims and said the firm was blamed for hooning that it had nothing to do with.
Mr Alim said some people mistakenly thought drivers racing or misusing cars in parking yards were his employees. The company used four yards altogether, he said. " ... there are other companies who use our park as well."
The yard a car was taken to depended on what spaces were available. Mr Alim said the company looked after some vehicles for as long as six months. He said of 3000 to 4000 cars parked over the Christmas holidays, there was only one customer complaint.
He also addressed poor Google reviews for the company, saying some were bogus, and "young guys" were getting a "kick" out of posting fake reviews.
His wife and fellow company director, Sakina Bano, said her husband gave the driver in the dashcam video a job out of generosity and now regretted it.
One Herald reader said her car was returned from Park n' Fly with a dent.
Another said the initial drop-off point looked good "but within minutes your car is driven 'hard out' to another site, away from view ... "
And Rick, who asked his surname be withheld, said when he collected his car, the fuel gauge was down by a quarter of a tank.
The company said drivers who left cars with Park n' Fly were often in a rush and didn't always thoroughly check their cars before jetting off. Some had no idea how much petrol they had.