O.k....let me clarify this one more time. You do NOT have to have weighted tags on an SUV, no matter how much weight you haul.
No, the statutes aren't exactly clear, and you have to jump all over the place in them to see all the related statutes, (which is why I'm not going to even try to post them here). However, I have talked directly to DMV about this, and not the peons that work in the offices, the policy makers themselves. DMV interprets "property-hauling vehicle" to INCLUDE pick up trucks, but NOT to include SUVs.
You can take my word for it or not, but I'm done stating it.
As an aside....even if your tow vehicle does not need weighted tags, you may need a Class A drivers license (non-commercial) depending on the weight you're hauling, i.e. over 10,000 lb being towed needs a Class A.