Ive driven a 130I si, the new shape BMs are brilliant cars everyway but dynamically they need too much modifications to make them any good, BM dont even fit LSDs to them anymore, IMO rear wheel drive without anm LSD is feckin pointless it makes it hard to get the rear end out and there is no grip what so ever If you want a BM buy an E46 M3 ive had one of those before and it was great.
Ill say this for the 130 though its a feckin brill engine, if you want handeling to match you are looking at 5k, the set up is sh*t no LSD, and to add to the rear wheel grip because BM have been cheepos and not fitted an LSD they have firmed up the springs and gave it a useless 12mm rear ARB
which makes it wobbly as fook ! if you add thicker ARBs say good buy to 30% of your rear wheel grip !
solution
LSD
Suspension
ARBs
Mounts
fitting
buy buy big chunk of money