I just converted to a larger rotor in the rear of my 07 R/T. Installed all Raybestos. The front rotor of the R/T is 345mm. The rears were originally 320mm vented rotor. I ordered the MOPAR caliper bracket 5175065AB (2, one for each side). Then installed 350mm rotors (the size of the police rotor) in the rear. The police pads from Raybestos is a semi-metalic (probably not the best option for DD street). they are pretty cool looking, because it has a police badge symbol on the backing plate. I opted for ceramic pads over the police pads. Both the front and rear rotors (from Raybestos) were by far the heaviest passenger car rotors I've encountered. The stock Bosch rotors were tore up, like the pad just ate the rotor away (don't know why, I bought car with 24000 miles and it look like that then). Now has 45000 miles. IMHO I'm not very hard on brakes. After I unpacked the rotors, I washed the cosmoline (sp) off in the solvent tank. then I washed the solvent off the rotors in hot soapy water so that you could see the pores of the rotor. The MOPAR brackets did not come with grease cups, so I gently removed the grease cups from the old bracket and installed them on the new brackets. The pad sets come with new abutment clips. I lube them with silicone brake grease (also included) and installed the new pads. Between last night and to and from work today, I was extremely easy on the new brakes and followed manufacturer brake burnish procedure. Near the end of the day, it felt like the pads really started to seat in and braking is exceptional. I'm not joe racecar driver and am just looking for a reliable brake system that will last longer that the Bosch setup. I don't know this for a fact, but IMHO the 320mm is satisfactory for the 18 inch wheels, but I prefer the larger rotor for the 20s (I don't have any engineering proof that this is so). So depending on your needs, you'll have to choose the products for your needs.