GT20v, i not sure what cheap u mean.
but i have 1 shop to recommmend which is at damansara perdana (behind the mutiara damansara, the curve shopping mall). if not mistaken the shop name is pro-care. RM168 for 3 layers(remove, polish and wax), they use 3M product. include interior. They really work on each inch of your car, really good workmanship i can said.
I recently installed a areospeed manual boost controller... I turned the boost to 1 bar.. It feels much better then.. And few days ltr, the car feels heavy.. According to the boost meter, the boost was climbing up...