Either way that you two wieghed your quads are NOT accurate. The best way with a "bathroom scale" would be to use one. YOu would have to balance the quad on the bumper 0n a single scale with some help of a freind to steady it.

 

Well i got to say it was perty accurate. I weighed my stock bike first and it weighed 489. I have to add the two scales together to get the total. I will have to try the one scale idea but I don't think my scale can handle it. On the plastic care...I know this sounds crazy but try using baby powder on your plastic ...It will bring the shine back....try it on your chrome also.