How do I attach a four page PDF Carfax report to my listings page??

Unfortunately, CARFAX reports cannot be sent through the CarGurus messaging system at this time. However, you can share your email address or request theirs and send it that way! Feel free to mention in the description section of your listing that this is something you are willing to provide for prospective buyers. Additionally, you can send screen shots of the report through the messaging system if that is easier for both parties.