With the built in configurable Xbox controller feature of LCPDFR why would anyone want to download Xpadder? I not being thick here I really would like to know what Xpadder does different/better than the in game support? Why use it?

I use it to control my ELS. The only real buttons I've mapped with XPadder is the D-Pad. Everything else has a function in game that I don't want to duplicate in Xpadder. So the Up, Down, Left, Right control siren change tone, air-horn, lights stage up one level and siren off regardless of lights stage. This makes driving so much easier and being able to do some great siren intersection clearing combos and control all the lights. 

Ahhhh I see. Because the built in function of LSPDFR doesn't have any ELS lines in the controller code you use Xpadder to assign those. I get it now. Thanks for taking the time to answer my question.