Car door magnet fitting and care

A car door magnet stays put and keeps your paint in good condition when it goes on a clean, dry, flat steel panel and comes off once a week so both surfaces can be cleaned. That is most of it. The rest is about where not to put it, taking it off before car washes, and storing it flat so it keeps its grip.

Check the panel first #

A magnet only grips steel. Before you order, hold a fridge magnet against the door where the sign will go. If it will not stick, a car door magnet will not either. Many vehicles now use aluminium, plastic or composite panels on some or all of the body, and even steel doors can have a plastic trim strip across the middle.

Then look at the shape of the panel. The magnet needs a flat area at least the size of the sign. Avoid:

• Swage lines and body creases, where the magnet bridges a gap and air gets underneath.
• Door handles, badges, rubbing strips, trims and mirror bases.
• Door edges and shut lines: the magnet must not cross the gap between two panels.
• Windows, lights and number plates. A sign must never cover or obscure them; the government page on displaying number plates explains the rules on plates.

Choosing a car door magnet size

Our car door magnetic signs are printed on 900µ magnetic sheeting in our Manchester workshop, in A3 (297 × 420 mm), A2 (420 × 594 mm) and common sizes of 450 × 300 mm, 600 × 300 mm and 610 × 457 mm, or a custom size from 100 mm up to 1000 × 600 mm. They start from £15.89. Measure the flat area of your door with a tape before you choose, then pick a size that leaves a margin of a few centimetres on every side. For vans, magnetic van signs go up to 1000 × 600 mm.

What you need #

• A bucket of warm water with a little car shampoo, and a soft microfibre cloth.
• A dry cloth or towel.
• A tape measure, and a piece of masking tape if you want to mark the position.

How to fit a car door magnet #

1. Wash and dry the panel. Clean the area with car shampoo and water, rinse and dry it completely. Grit trapped under a magnet scratches the paint and stops it sitting flat.
2. Clean the back of the magnet. Wipe the magnetic side with a damp cloth and dry it. Dust and road dirt on the back matter as much as dirt on the car.
3. Mark the position. Measure from a fixed point, such as the bottom of the window, so the signs on both sides of the car sit at the same height. A small piece of masking tape helps.
4. Offer it up by one edge. Hold the magnet by two corners, place the top edge first, then let the rest roll down onto the panel. Do not slide it into place, which drags grit across the paint.
5. Smooth it down. Run a flat hand from the middle outwards so there are no air pockets and every edge is in full contact, especially the leading edge that faces the front of the car.
6. Check before you drive. Try to lift each corner with a fingernail. If any edge lifts easily or sits over a curve, move the magnet to a flatter spot.

Weekly care for your car door magnet #

Take the magnet off at least once a week. Moisture and fine dirt collect behind it, and left for weeks they can mark the paint or leave a patch that looks different from the rest of the door. Wash and dry both the panel and the back of the magnet, then refit it.

A few habits keep it in good shape:

• Remove it before a car wash. Brushes and high-pressure jets can peel it off, and it can be damaged or lost inside the machine.
• Remove it in very hot or very cold spells if the car stands for days. Heat softens the sheeting and a frozen magnet can be hard to lift without bending it.
• Do not fit it to fresh paint. If a panel has just been resprayed, ask the bodyshop how long to wait.
• Lift it off by a corner, never by bending it. A creased magnet does not sit flat again.

Driving with a car door magnet at speed #

A car door magnet that is clean, flat and fully in contact holds well at normal speeds. The risk comes from a lifted leading edge: air gets under it and can peel the magnet off, which is a hazard to the driver behind. Check the signs every time you set off, and again before any long motorway run. If a sign has been knocked, parked against a hedge or had a corner curl, refit it before you drive.

If you drive a licensed taxi or private hire vehicle, check with your council’s licensing team before fitting any signs. Many councils have rules on what may be shown on licensed vehicles. Our taxi magnetic signs are printed to your artwork, so you can match whatever your licence allows.

Storing magnets when they are off the car #

Store the magnet flat, print side up, somewhere dry and at room temperature. Never roll it tightly, fold it, or leave it on the parcel shelf in the sun. The best place is flat on a steel surface, such as the side of a filing cabinet or a fridge, where it stays straight. Do not stack magnets face to face, and keep them away from bank cards.

If you want signs that stay on permanently, magnets are not the answer; see our guide to applying vinyl stickers for self-adhesive graphics, or browse the full vehicle magnets range if magnets suit how you work.

Still not sure? #

If you are unsure whether your doors are steel, or which size will fit, send us the make, model and year and we will help. Call 0161 315 1151 or use the contact form. Car door magnets dispatch in 5 working days on standard, 4 on express and 6 on saver after your order and artwork are confirmed.