Where/how Do You Store Your Truck? in Antique and Classic Mack Trucks General Discussion Posted October 7, 2005 David is exactly right. Tarps are a big NO-NO! They hold lots of moisture that will condensate and then recondensate.My grandpa was a firm believer in tarping his Ford tractor (after he ran out of room to keep it inside). After just 5 years, it not only had surface rust. But, serious rust-through and rot on it. Tractor only had 300 hours on it. But, it looked like several thousand. There are companies that make custom car covers that are "breathable." But I'm sure for your firetruck, they would charge you a small fortune.