The word "undercarriage" refers to the parts of a vehicle that are located underneath it, such as the wheels, brakes, suspension, and framework. Full definition
It also has severe rust on undercarriage of the car. (autolist.com)
This Jaguar has no rust on undercarriage or body. (autoclassics.com)
Look for the best lightweight jogging stroller that features an extra large undercarriage basket which will perfectly fit your diaper bag. (earlymomentsmatter.org)