Answer
The most-popular sizes for vehicle magnets are 10" x 20" for smaller passenger cars and 12" x 24" for SUVs and pickup trucks. For bigger vans or trailers 18x24 or larger is popular. We can print up to 48" Height x 300" Width.
Industry-specific considerations: For commercial trucking, DOT magnets displaying DOT numbers are commonly ordered in 18" x 24" sizes to meet 2 inch letter height Department of Transportation visibility requirements. landscaping magnets for lawn care and tree service companies typically work well in the 18" x 24" size for pickup trucks,
One common mistake people make in ordering their custom car magnets is to assume that "one size fits all" or simply guess at the dimensions. Not all car doors are designed the same way. Car magnets should be ordered at custom sizes to ensure the best fit on the vehicle. If car magnets are placed over and area where the door is curved or has trim, air may flow between the car and the magnet. This creates an air pocket (which could result in the sign falling off because the magnet cannot contour perfectly along the curve).
Always measure the flat metal surface area on your car door before you order. This is strongly-recommended and is the best way to pick the size of your car magnets.