How to Install a Roof Box to Car? Step by Step (2023)

We’ve experienced such a scenario more or less in our life – imagine you’re on a road trip with your friends and family. You’ve packed a lot of bags. What’s now? People inside the car can’t even move freely! So much disgusting isn’t it?! But, what’s the solution to this problem? The answer is roof box.

A roof box can save you from such a dilemma. Hence, it will work as an additional room in your car! You can put your belongings in it. However, you’ve to ensure that it has been attached to the car properly. In this article, we’ll talk about how to attach a roof box to a car – Step by step guidelines. Let’s jump –

How to Attach a Roof Box to Car? Installation Process

Before discussing how to fit a roof box in the car – we should learn what a roof box is?

A roof box is a massive suitcase positioned in a car that can hold many personal things. On top of that, it is fittable to the roof rack system of the car’s roof.

As the name suggests, a roof box is attachable to the rooftop of a vehicle. It is sturdy and foldable. If you have to carry a lot of personal belongings in your car, you either have to buy a big car or invest in a roof box.

How to Install a Roof Box?

Many people have a delusion that fitting a roof box in the car is a complicated task. But, it isn’t. The procedure is quite simple and quick. Here, we will give you proper instructions on fitting a roof box. On the contrary, you’ll need some equipment before installing a roof box.

Needed Equipment

  • Fastening rods
  • Protective gloves
  • Screwdriver

Step 1 – Install a Dome on the Roof

At first, you’ll need a roof rack system in your vehicle to install a roof box. This rack can be locked with the box. Besides, your vehicle might possess a roof rack already. You’ll have to be aware of the mounting system used by the box. In today’s market, two types of roof rack mounting systems are most popular. They are –


The name says it all. Yes, the U-bolt system is similar to the English letter “U”. Additionally, these systems can easily fit in the roof bar cross-section. These types are adjustable with each roof bar. So, this is a plus.

However, if you’re a T-track adapter user of Thule’s wing type roof bars, you need to purchase a T-track adapter. This adapter can fix the Thule’s specialized roof bars in a short period.

Power Click Mount

This is another highly used mounting system. You could mostly see them in SUVs. Hence, this system uses claw grips.

Step 2 – Put the Rack across the Cross Members

Since the roof bars are in the right place, time to make another move. Put a trunk on them. Henceforth, you should make sure that you’ll be able to open the rack without facing a hassle.

Step 3 – Tie up the Roof Rack to the Roof Rails

Now, the roof box is safe and secured; you have to tighten the fastener with all of the might around the rails.

Step 4 – Closely Check the Bond

We can assume that you’ve successfully secured the rack. Further, you’ve to confirm that the thing is fastened correctly. Otherwise, you could face problems while driving on the road. Try to follow the rules of PTAC (Total Permitted Loaded Weight) set for the automotive that showed in your document.

In addition, follow the maximum weight of the belongings that a roof box can carry.

How to Attach Roof Box to Car

What can be the Best Place for a Roof Box on a Car?

The foremost thing you’ve to do is to distribute the weight evenly. For this reason, you will have the chance to resist any future mishap that could happen while driving on the road.

Henceforth, if the overall quantity is heavier on the backside of the roof box, it will move to different places at a high-level speed in case of an emergency exit.

As a result, the personal belongings will ruin surely. Even the body of the vehicle can get consumed. So, the best way is to mount the bars and boxes according to the manufacturer’s guidelines. However, while packing the roof box, you should be aware of the overall situation to avoid such a situation.

Things to Consider Before Buying a Roof Box

There are some crucial matters you should consider before purchasing a roof box –

Roof Bars

It’s necessary to check on the roof bars before buying a roof box. You can’t connect a roof box properly without the help of a roof bar. Additionally, the roof bars are attached to a vehicle’s roof side. The roof box fastened on that place.

Build Materials

“Money can’t buy happiness” – yes, it’s true! But, money can definitely buy a better roof box! The more money you’ll spend, the higher quality you’ll receive. Hence, the cheaper product won’t be durable, long-lasting, and made from flimsy plastic.

That won’t certainly be your goal. Right? So, spend more money and buy a good one.


What sizes do you need? Think thoroughly. Do you need a bigger or a smaller one? If you have to visit for a shorter time, try considering a small-sized roof box. On the other hand, longtime trips require larger-sized boxes.

The Openings

Most of the boxes possess a single opening system. They are openable from the left side to avoid any adverse incidents during travel. Besides, dual-opening is perfect if you travel abroad. You can open these boxes from left or center side of the box.


Your roof box should possess an aerodynamic design. It has to be built in a way as wind resister as much as possible.


  • Do I need roof bars to set up a roof box?

Of course. Roof bars are crucial to set up a roof box. Roof boxes are the perfect product to store your luggage during traveling. But, if you can’t install them correctly, it could bring massive problems. Therefore, roof bars are crucial since you can insert roof boxes properly into them.

  • Can I set roof boxes in any roof bars?

Ermm…yes… You can do it. But, there are always exceptions. For instance, some boxes hold more oversized items like skis. In that case, you might need extra bars.

  • How much money do I have to spend to buy a roof box?

The price of a roof box depends mostly on size and brand. However, most roof boxes will cost around 100 to 300 euros. A very few percentages will cross 500 euros.

Final Words

So, we hope that our article will give you a broad knowledge of how to attach a roof box to your car. Further, you can still consult with an auto professional regarding it. You can even make contact with the manufacturing company too if you still looking for a solution.

So, what’s your take regarding our article? Do you have any more questions? Feel free to ask in the box below.

-our editorial board has reviewed this article and has been approved for publication according to our editorial policy.

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Meet the Author

Adolfo VonRueden is an experienced automotive professional specializing in car roof boxes, roof racks, and rooftop carriers. Learn how Adolfo got his start as expert in rooftop carriers, and why he decided to start this car roof box blog. If you want to send Adolfo a quick message, then visit his contact page here.

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