Cops and state patrollers take classes on how to target people in cars passing through their states. It's big for cops, and big for consultants. https://www.mttuiv.org/files/AssForfDFoulkBIO.pdf
that's exactly why it has survived without review for this long. the courts can't just order an investigation the way, for example, Congress can. the judicial system requires either a criminal complaint (filed by the states' attorney) or a civil suit (filed by the injured party) in order to take up a case and examine the relevant law.
this won't go anywhere until a victim of civil asset forfeiture sues the police department. that is EXTREMELY hard to get away with. Police have the "thin blue line" mentality and will go to extraordinary measures to protect their own tribe.