just sold my 04 reg cab k.n magnaflow silver i then bought new 06 reg cab msrp 51,000 they gave me 30,000 for my 04 and took off 15,000 msrp the06 is so much improved its loaded and cover,nav. all the toys i put volant ram air cold air box then put x-pipe with two magnaflow glasspacks about 16 inches long , its got such a throaty wild sound, i'm not going any further because any ford wants some i will stomp his *** it runs that well, i'm sure in couple of years it will be worth a lot more but i love this truck and no more after this oh yeah and its inferno red also gets better gas mileage than 04 plus faster.