Nope, actually they dont use any tool. (I asked them and they told me they use something called "Prop clipping" It needs dedication and effort in every single jump they do. i added so many races from those pro creators that someone forgoted to delete the ramps that gave me a hint on how they make those things. and now, i know how to those type of things. JUST A LITTLE BIT, THEY ARE STILL PROFESSIONALS. ) i have been playing lately whit a group of people which are dedicated to the creator and when i see them playing gta they are almost all the time on the creator or playing races) its actually pretty facking cool. And actually, you guys have seen nothing. And yes slayer, theres already a race that its almost like a SA-MP mapping style. I will promise you guys that i will show you the best work from those guys, because in my opinion they deserve to be famous.
Sorry for bad english skills. xD