Modding Filter

I have seen various reports around the section regarding the new "mod shield" that Nexon has employed. I was just wondering;
1) What are the suspected theories about how the shield works?
2) What methods are people using to circumvent the shield?
3) What types of mods still work, and what types are completely dead?

Thank you for help a n00b (me) understand this new (slightly stupid) move by Nexon.

1)First people suspected it was because of size, that was untrue. I'm not sure what other possibilities there are.
2) registry edit
3) textures only, with registry edit, all
Also I don't think the mod shield is stupid at all, for a change nexon did something smart.
I know for a fact that supercarz knows how, and I suspect that a few elite modders know too.