Modifications to a car, pick - up truck, van, motorcycle, or moped can affect its registration class. Important : The DMV cannot examine your vehicle to determine the correct registration class. You must determine the correct registration class for your vehicle. 

Modifications to a motorcycle or moped, including Limited Use Motorcycles- 
If you remove a speed governor that was originally installed to limit the top speed of a moped or add a speed governor that limits the top speed of a moped or motorcycle , you must notify DMV and register the moped or motorcycle in the appropriate class [1]. 

Modifications to cars, pick-up trucks, and vans 
Part 106 of DMV Regulations describes the vehicles that are registered in the' Commercial' class and in the passenger class. Part 106 also describes how some modifications that you make to your vehicle can affect the correct registration class of your vehicle. A description of the modifications appears below. Each description includes a reference to the DMV Regulations [2]. For all vehicle modifications , you must obtain a vehicle weight slip. You can get vehicle weight slips at most vehicle and/or metal scrapyards and from some auto - parts stores and mechanics, especially those specializing in vehicle modifications and camper body / equipment sales and installation. 

Modifications that change a registration from 'Passenger' class to 'Commercial' class 


Cars (Part 106.2 (e)) 
You can register a car in the' Commercial' class if all the seats behind the driver are removed. Instead of the seats , you must install a permanent box or permanent rack to carry cargo. 

Station Wagons and Vans (Part 106.2 (f)) 
You can register a station wagon in the' Commercial' class if all the seats and all the seat fittings behind the driver are removed completely. 

Modifications that change a registration from 'Commercial' class to 'Passenger' class 


Pick-up Trucks (Part 106.6 (b) and (c)) 
You can register a pick - up in the' Passenger' cla

user: I want to make some modifications to my vehicle, but I'm worried that I might change its class. Care to elaborate a bit about such modifications and how they affect the class rating?

assistant: Of course. Are you planning to modify a car?

user: Yes, I wanted to modify my car.

assistant: You can register a car in the 'commercial'  class if all the seats behind the driver are removed. Instead of the seats, you must install a permanent box or permanent rack to carry cargo.

user: Alright. And if I remove the speed governor of my moped?

assistant: Then you must notify DMV and register the moped or motorcycle in the appropriate class.

user: I love to tinker on all kinds of vehicles, I'm an auto-mechanic. So which modifications would change a registration from commercial to passenger class?

assistant: Are you planning to modify a pick-up truck?

user: No, unfortunately I don't have a pick-up to modify.

assistant: Are you planning to modify a van?

user: Yes! That would be my next modification project.

assistant: You can register it in the 'passenger' class if the van has at least one side window behind the driver, and at least one seat or set of seat fittings that is installed behind the driver.