Subaru Outback Manuals 2014 Outback Owner's Manual | Page 734

8-24 Driving tips/Trailer towing & Trailer hitches WARNING Never drill the frame or under-body of your vehicle to install a commercial trailer hitch. If you do, dangerous exhaust gas, water or mud may enter the passenger compartment through the drilled hole. Exhaust gas contains carbon monoxide, a colorless and odorless gas which is dangerous, or even lethal, if inhaled. Also, drilling the frame or underbody of your vehicle could cause deterioration of strength of your vehicle and cause corrosion around the drilled hole. CAUTION . Do not modify the vehicle exhaust system, brake system, or other systems when installing a hitch or other trailer towing equipment. . Do not use axle-mounted hitches as they can cause damage to the axle housing, wheel bear [