Extended Customization v1.2 - Now with more helis

Fan of Saints

Modding patch tester
I installed this, but after I did I couldn't edit non customizable cars and it deleted some vehicles from my heliport like the saints VTOL. Do I need a clean save for this or is it just bugged?
I have A question on installation-I have Things To Do In Steelport Mod and it has An 'Optional Mods' folder in it for additional mods. Can I just simply add the folder in there or find another method for installing this mod. Help would be appreciated on this matter. Thanks! :D