I just switched from a Mercedes S-Class AMG to an LS 460L. I love everything about the new Lexus, but I would like to put wider tires on the back to give it a wider stance like the AMG pkg on the Mercedes. Right now, my car takes 245-45-19's. The tech at the dealership advised me not to go wider because of the wheel wells on this car. Does anyone know if I can go a little wider? And if so, can I use the same 19 inch rims on the 460L?