Darren Drake Combatting 21st Century Weapons of Terror Act or the Darren Drake Act This bill directs the Transportation Security Administration to: (1) conduct a study on the various types of information collected by rental companies and dealers that rent a truck, tractor, trailer, bus, semitrailer, or van with more than 15 passengers (covered rental vehicle) in the United States and Europe, and (2) develop and disseminate best practices for rental companies and dealers to report suspicious behavior to law enforcement agencies at the point of sale for such a vehicle. The Department of Homeland Security (DHS) shall establish a pilot program, for a period not to exceed one year, to: develop a uniform standard for the type of information collected by rental agencies and the type of information used in submitting suspicious activity reports; provide operators with a threat assessment prepared by DHS regarding the terrorism threat of large vehicles; distribute guidance for improving the suspicious activity reporting process, including training for designated employees to better identify suspicious activity; provide technical assistance to operators to better access suspicious activity reports; and establish a procedure for checking information against a designated watch list that does not contain any classified information, and for dealers and rental companies to provide notice of a sale or rental to the Federal Bureau of Investigation, if determined necessary by DHS. A dealer or rental company shall not be liable for any action taken in accordance with this pilot program.