Had the same problem here. The hubcap has 5 pegs that press against the steel wheels. Either they wear down over time or their just not molded long enough but the will squeak and rattle no matter how tight you torque the plastic lugs. My solution: get some 3/8 rubber Fuel line and cut it into 5 one inch pieces. Shove one on each of the 5 hubcap pegs about 3/4" leaving about 1/4 over the end. Reinstall the hubcap and gently press on the hubcaps rim till flush with wheel. Six months later and still no rattles. Two feet of fuel line should do the trick and it's cheap.