Doing your own vehicle repairs is not only satisfying but it also can save you a lot of money. This is particularly true for easy jobs like replacing worn-out spark plugs, changing your oil, or replacing your brake pads.

There are some types of repairs, however, that are best left to the pros.

Here are five of the top DIY car repairs that you should avoid doing on your own:

1. Transmission repairs

Out of all of the parts on your vehicle, the transmission is one of the most complicated. It is made up of tons of different parts and components that all work together in perfect harmony to keep your vehicle running. Since the design is so complex, it takes a lot of experience and expertise to make repairs without causing further damage in the process. Even though transmission repairs are extremely expensive, this is one job where it is worth paying for professional help to ensure that everything is done right.

2. Bodywork

Any damage to the body of your vehicle should be professionally repaired. It is almost impossible to get professional-quality results when doing bodywork or cosmetic repairs at home.

Whether you are trying to remove dents or apply new paint to an area where the original paint was damaged, your results will almost always be subpar if you try to do them yourself.

If you take your car to a body shop, on the other hand, the repairs will be practically invisible, making the extra cost worthwhile.

3. Electrical system repairs

When you really stop to examine your vehicle, you will most likely be shocked by the sheer number of wires running throughout it. The electrical systems in today’s vehicles are extremely complex.

While you can handle minor repairs like swapping out a blown fuse on your own, any major repairs involving the electrical system will usually require professional help.

4. Replacing your timing belt

Even though it seems like swapping out your old timing belt for a new one would be an easy task, a lot can go wrong during the process. The hardest part of this job is accessing the timing belt itself. You have to disassemble a large portion of your engine to reach it.

If you don’t get things exactly right when you are putting them back together, it can cause major problems with your car, leading to even more expensive repairs.

5. Repairing or replacing your windshield

If you have a cracked or damaged windshield, you may be tempted to try to repair or replace it on your own. Although you can purchase windshields from junkyards for very little money, they aren’t as easy to install as you might think.

You have to buy a lot of specialized tools and equipment to secure them in place. By the time you buy everything you need, you could have just paid to have a brand-new windshield installed by a professional.

While there are some DIY car repairs that you can do on your own, you should avoid the ones listed above.