When I know I am going to place someone in custody during a traffic stop, I don’t take them out of the car at all. They are at a disadvantage when they are seated.
First I ask them to turn off the vehicle to ensure that they don’t try and drive away. Then I tell them to turn their body away from me and place their hands behind their back. I don’t tell them they’re under arrest yet, so in their initial confusion they will usually will comply. Before they even realize it, it’s too late and the cuffs are already on.
This method works for me especially when the suspect is a lot larger than me. I explain everything to them after the cuffs are on and while I’m walking them to my car. The key is that element of surprise.