WE love our old cars in Ireland but one of the biggest killers of classic vehicles is rust. I’m the owner of a few retro machines and rust has always been something I struggled to keep under control.

If your car survived winter, a rust inhibitor can help it survive the aftermath.

New car dealers almost always offer it when they close a deal: third-party rust warranties, or products that purport to prevent rust. Richmond Hill, Ont., resident Margo Sullivan said she thought the ...