Getting a car wash is definitely one of the more fun car maintenance tasks, especially when the kids are in tow. Not only does a good car wash leave your vehicle looking brand new, it can also help to keep it functioning properly and maintain its resale value.

If you’ve been in line for an automatic car wash lately, you know it’s not just as simple as deciding to drive your car through the tunnel. There are a whole host of extra services you can opt to get, and choosing which ones – if any – are needed can be a bit of a headache. So the next time you’re in the market for a car wash, here’s the lowdown of the typical offerings, and the verdict on whether they’re worth the up-charge.

Undercarriage Wash

An undercarriage wash is exactly what it sounds like. While you may not necessarily be able to enjoy how fresh and clean your car’s undercarriage is, getting this part of your vehicle cleaned is a good idea, especially if you drive through lots of mud or live in a cold climate where roads are salted. An occasional undercarriage wash can go a long way in preventing rust and corrosion in your vehicle.

Verdict: Worth it. Rust and corrosion can wreak havoc on your car. Of all the extras offered at the car wash, this is really the only one done for reasons other than cosmetic. Once per year is the typically recommended frequency for this service.

Wheel Cleaning

As it turns out, wheel cleaning is purely for aesthetics. This service targets the dirt and grime that gets trapped in your car’s wheels. However, its brake dust – the metallic substance that comes off the brake pads – that’s the main culprit of wheel staining and leaves permanent marks on wheels. Unfortunately, the only way to get rid of the stains left by the brake dust is to sand blast and refinish your car’s wheels.

Verdict: Not worth it. Since wheel cleaning won’t be able to remove all the stains on your wheels, you’re really not getting a lot of bang for your buck here. Plus, opting out won’t cause damage to your car or jeopardize its ability to brake, so you’re probably better off saving your money.

Spray On Wax

With advances in car finishes, waxing is far less important than it used to be. While waxing will still add some shine and water resistance to your car’s finish, spray on waxes aren’t as beneficial as hand waxing (although they’re much quicker and are generally cheaper).

Verdict: Probably not worth it. Spray on waxing is a purely cosmetic service that’s not necessary for your car’s maintenance and not as effective as a hand waxing. But, if you’re looking for a quick boost in your car’s shine at a fraction of the cost of a hand wax job, this could be a good thing to consider.

Rust Protection

The application process for rust reducing products is so intensive, it’s unlikely that a quickly sprayed-on solution at a car wash will be effective. It’s also worth noting that the rust protection industry has been in some hot water lately with allegations of fraudulent claims against its products.

Verdict: Definitely not worth it. If you’re really worried about rust and want a protective product applied, you’re better off taking your car to a proper detailer where their application and product selection will be more careful.