learnwithjaclyn/TikTokIf you're in the market for a used car, Facebook Marketplace can be a surprising goldmine. But one Texas-based TikToker says there are a few things you need to keep an eye out for if you want to take advantage of the secondhand site.Fortunately for the rest of us, she was more than willing to share her tips with her followers in an informative video that she posted on the social media platform.Apparently, @learnwithjaclyn's tips really resonated with people, because her advice video quickly went viral, generating thousands of views in the days after she posted it. AdvertisementAdvertisementThinking about buying a used car? Or else wondering what you should know if you someday decide to? Check out what Jaclyn has to say about the process (and what commenters say she got wrong).TikToker Says High Mileage Vehicles are a No-NoJaclyn starts off her video by telling folks to avoid any cars with more than 100,000 miles on it. However, people in the comments said you shouldn't necessarily be scared of these often-driven vehicles, especially if you can verify that they've been well cared for. "Don't be scared of 100,000+ miles depending on the car and only if they have records of their service," one commenter wrote.Avoid Sellers Who Have a Lot of Listings or Who Are New to the ServiceNext, Jaclyn shares her biggest red flag: people who have multiple cars listed for sale. "If their whole job is selling cars you don't want to buy from them," she said, adding that she believes that these people are more likely to keep any issues a secret. AdvertisementAdvertisementShe says you'll want to check their profile to confirm whether they frequently post cars for sale. While you're there, you'll also want to follow her next tip: make sure the seller didn't recently create their account, as this can be another red flag.Read Through the Description of the Car and Do Your ResearchWhile it may seem like a no-brainer, Jaclyn says checking for a detailed description of the car is also important. This is where the seller should provide information about the car's condition, including both cosmetic and mechanical features and flaws. If everything looks okay at this point, she suggests contacting the seller to obtain the Vehicle Identification Number (VIN) so you can research the vehicle's history and value using services like Carfax and Kelley Blue Book. Once you've checked this out you'll want to go see the car in person, which Jaclyn says is the perfect time to bring along a friend who knows a bit about cars so they can help you check it out.Then, when you're driving the car, you'll want to test it out at a variety of speeds, which could mean hopping on the highway.You Need to Verify the Status of the Car's TitleJaclyn's last piece of advice is another one that some people disagreed with. In the video, she says that the car's title should be 100 percent clear and not a "rebuilt title." If you're unfamiliar with the rebuilt titles, CarGurus says that is what is issued when an insurance company has previously declared the vehicle a total loss due to damage, which could include everything from a flood to an accident. AdvertisementAdvertisementHowever, rather than being scrapped, the car was likely purchased by a rehabber who rebuilt it to make it roadworthy again. But commenters once again said that you don't need to automatically write these cars off, especially if you are a little car-savvy. "Nothing wrong with salvage titles as long as you know what you're looking for," one person wrote. "You'll never get a perfect vehicle! But you will and can find one that's good for you."And there you have it. While Jaclyn's advice seems to cover a lot of ground, you should do your own research before buying a used car on Facebook Marketplace, and be sure you're not missing any obvious (or not-so-obvious) red flags.If you want more stories like this, follow Guessing Headlights on Yahoo so you don't miss what's coming next.