Protection First Class offers an inexpensive alternative to rubberized undercoating.  PFC rust preventative remains soft and flexible, and actually heals itself and continues to coat long after other water soluble or solvent based products have evaporated or worn off.  Another great feature of PFC is that its translucent film is easy to see through and diagnose problems before they happen, unlike rubberized undercoating that masks the problem and allows rust to grow and spread under its surface!  It lasts for up to a year, is easy to remove, and inexpensive and easy to reapply. To apply, first clean vehicle thoroughly and remove and scaled rust.  Shake PFC liquid thoroughly before filling the spray gun reservoir, then apply an even coat of product to the vehicles undercarriage.