Patrick Dempsey looks dapper in pinstripe suit as he stops for fans in NYC to promote Ferrari: 'It was the best job I've ever had in my life'

Patrick Dempsey thrilled fans who had been waiting for hours in the cold Monday morning, signing autographs for them as he exited the ABC Studios in New York. 

The 57-year-old actor looked handsome wearing a black pinstripe suit with a navy blue mock turtleneck sweater that highlighted his dark blue eyes.

The Enchanted actor made a scheduled stop by Good Morning America to talk about his upcoming film, Ferrari, which opens in theaters Christmas day.

'It was the best job I've ever had in my life,' he told hosts Robin Robert and Lara Spencer.

'I was in Italy driving cars, making a movie with Michael Mann, having great food, cycling on the weekend. It was an extraordinary experience with some great actors.'

Those great actors include Adam Driver as race driver turned entrepreneur Enzo Ferrari and Shailene Woodley as his mistress Lina Lardi.  Patrick portrays racer Piero Taruffi. 

The actor, who has more than a decade of experience as a professional race car driver had been unknowingly preparing for the project for years.

'My proudest credit is at the end if you look [at the credits] I'm part of the stunt drivers,' he revealed. 

'The stunt coordinator called me early and goes, "Do you want to do all the driving?" I go, "Absolutely."'

The actor also dyed his salt and pepper hair a platinum shade to portray the racing legend known as 'the silver fox.'

'It took about a week to get the color right,' he told them, 'the first time it was yellow, and it didn't work and then, you know, I didn't realize you can just fry your scalp, and that started happening.'

The dedicated star said, 'Towards the end of the shoot, I had fried my hair so much, I had what's called a "chemical cut," my hair started falling off and falling out, so I had this "monk ring" around the back of my head where I had my helmet on, so that's when my wife shaved it all off." 

He said audiences who go to the movie to see 'great racing' will get their wish, 'but you'll also have a great human story as well.'   

The Grey's Anatomy alum also spoke about the impact the 11 seasons he spent on the show has had on his life. 

He revealed the drama 'has really inspired so many people to go into the medical profession and has given me the platform to be able to do the 'Ferrari movie.' 

He believes his part as Dr. Derek 'McDreamy' Shepherd inspired his being named People's 'Sexiest Man Alive' earlier this year.

'I think that's been the biggest gift coming out of that show, is to be able to do something positive and give back.'

The Made of Honor star founded the Dempsey Center in his home state of Maine in 2008, inspired by his mother's battle with cancer. Amanda Dempsey died from the disease in 2014.

The center does not treat cancer, but 'we treat the person holistically with wrap-around care," he explained.

'We do spend so much time and energy on research and developing the drugs that are important, but we forget about healing the human being," he contended, adding that the services offered are for 'Not only the patient, but the family and everyone around them that's been impacted.'