Q: plastic splash shield under car broken

Under engine shields keep water, dirt, and debris off of engine electrical components and also keep combustible debris from roadways, such as paper and plastic, from being drawn up into the engine compartment possibly contacting the hot exhaust manifold. So, you were smart to write in about this because the shield should be replaced ASAP. If you have the shield and it is not too damaged, for example if it only has torn mounting holes that can be covered with oversized washers or fender washers, it can be re-attached to the frame mounted "tabs". If, though, the shield is really mangled, this is a dealer only part and thus will have to be procured from a Ford dealer. Also, the under engine area beneath the shield should be inspected just in case the shield came off due to vehicle impact with something in the roadway. If you desire that the shield be replaced by a certified mechanic, and the lower engine compartment be visually inspected during the repair, please request a visit to your home or office using YourMechanic’s website inquiry form or YourMechanic’s toll free service number.