I'm planning a DIY Catalytic Converter guard for '17-'22 Primes.

Reason for DIY is existing after market are aluminum, which cuts pretty fast and easy, and I've got tools to cut steel, and some spare steel sheets, and I've got some 23" tall floor jacks coming, and I'll need to crawl fully under the car to finish running the Trailer Lights wiring under the car up to the battery.
Another reason is AFAIK there is only one commercial aftermarket, so it not impossible thieves would be familiar with it and be able to get past it. I want them going "What the heck? Never seen THIS, lets forget this one, can't tell how long it will take".
Any suggestions? I plan on Publishing the pattern on this forum to allow others to make one without first crawling under their Primes to take measurements.
I'd like to have as much open air as possible, because sometimes I'll run the engine with car parked to charge up battery. Seems commercial unit sold at Amazon doesn't allow much air circulation.
One feature I'd like to include, and will include this if I end up going with commercial unit, is wire ropes/cables on top of the shield wrapped around the mounting rivets. That will make slicing through even soft aluminum with a sawsall problematic as it will hang up the reciprocating thin blade. The cables will be hidden from view so it will cause unexpected problems after they are "committed" and have started making noise and their "clock is ticking". Maybe also two fairly thin layers of metal, to cause same effect.
I'll probably install into car's metal using common self tapping Philips screws, then intentionally strip out the heads so you'd need to drill them out, and/or fill with BJ Weld. Not impossible to remove but not something a Cat Thief is going to be ready for.

 

Pretty easy for me to cut thin steel with skillsaw and black-blade, and sawsalls etc. I might just run a few about 2"x1/4" U-channels, with steel cables hidden on top.

Another thing I'm planning is stashing a spare cell phone with charger somewhere semi-hidden, with cheap data plan and Family Finder app. At least I'd should be able to know where the chop shop is before they find the hidden phone. Cheap data plan costs same as GPS anti-theft subscription, and it always good to have spare phone aboard. Be nice if there was an App that would allow a phone to have tremor alarm that could armed/disarmed from another phone, so the alarm phone could remain well hidden.

Part of my upcoming running of Trailer Light wires will be a couple extra sets of wires to run big 12v from battery to trunk, and the compartments alongside trunk where the trailer wires run.