How do you decorate the wedding car?

Car decoration is one of the few wedding customs that is partly governed by somebody else's rules: the rental company's contract, the venue's parking lot and, at the edges, road traffic law.

This article covers the traditional forms and where they came from, what the rental companies will and will not allow, how to fit ribbon yourself without damaging paint, and the practical points that get overlooked, including what happens to all of it after the ceremony.

Three decorations recur across English-speaking weddings, and they belong to different parts of the day.

The ribbon is the one with a settled form. It runs from a point at the centre top of the windscreen out to the front corners of the bonnet, usually in white, ivory or a colour picked up from the flowers, in a width of about 75 to 100 millimetres.

The trailing cans are often said to descend from an older European custom of making noise to drive off bad luck. That explanation is repeated widely and is not securely documented; what is clear is that the modern version arrived with the motor car and has largely gone again, because venues and neighbours object and the string takes the paint off.

If the car is rented, the contract decides most of this, and it is worth reading before buying anything.

• Ribbon is normally included. Most classic and chauffeur-driven rental packages fit ribbon in a colour of your choice as standard, and the driver does it on the morning.
• Your own flowers are usually fine, but they are fitted by the driver, not by you, and only with non-marking attachments.
• Nothing adhesive. Tape, stickers and window paint are refused almost universally, and the damage clause on a classic car is not small.
• Nothing trailing. Cans, shoes and anything dragged behind are refused by nearly every rental company.
• Confetti is often excluded too, because it sticks to paint and gets into the interior. Check before the exit is planned around it.

If you are using your own car or a friends, you have more freedom and more responsibility. Magnetic backing and suction cups are the safe attachments; anything tied through a grille or under a bonnet catch needs checking for heat and for movement at speed.

One question worth asking the rental company early: whether they will do a second car, or fit ribbon to the cars carrying the wedding party. It is often cheaper as an add-on than arranging it separately.

Doing it well takes fifteen minutes and about 20 to 40 dollars of materials in the US. The method below is the standard one.

1. Wash the bonnet where the ribbon will sit. Grit under a ribbon at 50 miles an hour is a scratch.
2. Take two lengths of ribbon roughly three metres each, in 75 millimetre width. Two are easier to balance than one long piece.
3. Anchor at the windscreen. Tuck the ends under the top of the bonnet, close the bonnet on them, or tie both to a windscreen wiper spindle where the design allows.
4. Run out to the front corners and secure inside the bonnet catch or through the grille. Tension it so it sits flat but does not press.
5. Check the view. Sit in the driver's seat. If the ribbon crosses any part of the windscreen, it is wrong.

Two additions. A small ribbon bow on each front door handle is traditional and takes two minutes. And if you are adding flowers, keep them low and to one side of the bonnet, because anything tall becomes a sail and anything central blocks the driver's sightline over the nose of the car.

Do it the day before if you can, in daylight, on a dry car. Doing it at eight in the morning in a suit is how ribbon ends up crooked in every photograph.

Decoration is legal, but a small number of things are not, and they are the ones people improvise on the day.

Nothing may obscure the driver's view. That includes ribbon across the windscreen, flowers on the dashboard high enough to sit in the sightline, and anything hung from the mirror. In the UK this falls under general construction and use requirements, and it is the rule most often broken by a well-meaning relative.

The number plate must stay readable. Front and rear. A ribbon or a sign across a plate is an offence in the UK and in most US states.

Nothing insecure on the outside. Anything that can come off at speed is a hazard and, if it does, your problem.

Lights and indicators stay visible. Ribbon across a rear light or a sign over a brake light is the same category of mistake as the plate.

Venues add their own layer. Many will not allow confetti or petals in the parking lot, some restrict where a car may stop for photographs, and listed or historic buildings often have a specific route for arrivals. Ask when you book rather than on the day, and pass the answer to the driver.

Where the couple are coordinating several cars, the arrival order and the parking arrangements are worth writing down for drivers alongside the timings on the wedding website, since the people driving are rarely the people holding the schedule.

If ribbon feels too formal or the car is not a classic, the alternatives are simple and cheap.

• A hand-lettered board propped in the rear window, which photographs better than a printed sign.
• Eucalyptus or foliage garland along the front grille, tied rather than taped.
• A single bloom fixed inside each rear door, visible when the doors open for the photographs.
• Chalk pen on the rear glass, which washes off with water and is the only marking that is genuinely safe on paint-free surfaces.
• Ribbon on every guest car instead of an elaborate lead car, which turns the whole convoy into the decoration.

Then decide in advance who removes it all, because nobody plans for this. The car usually goes back the same evening, often to a rental company that charges for cleaning, and the flowers are wired to a bonnet that has been in the sun for eight hours.

Give the job to one named person, with a trash bag and a pair of scissors in the trunk, and agree where the flowers go afterwards. A bonnet arrangement transfers neatly to a table at the reception, which is the difference between one use and two.