We have the same problem where we live. All they need is a battery powered grinder with a cutting wheel and a vehicle they can crawl under easily. It typically takes them less than a minute and most people nearby have no idea what they are up to.
A Sawzall with a Diablo blade is much faster, just in case anybody wants to get into the business....
Honda vehicles are a prime target. Honda has now started putting the converter in the engine bay. That is where mine will be in my next vehicle