CS tyre at Jalan Air Putih, beside Eng Hong Supermarket I think, is ok. One of the few places that actually 'torques' the wheel nuts. Theres also a shop near Shell, opposite of MS Garden, which I've seen some conti cars. But CS would by my 1st choice.
I went to the shop near Shell opposite the MS Garden, good service but make sure the supervisor handles your car and not the helpers, they probably have not much experience with bmws.