Like "Lozo" said...
BG is a chasis code stands for all mazda 323 model from 1989-1993.That includes all Familia,Interplay,and Astina..
Ford also had came out model that look a like and using the BG technology from all parts (Engine,Absober,Wiring and ETC..)accept body look known as KF/KH.For all Ford Laser Model includes Ford Laser H/B,Ford Laser Sedan and Ford Laser TX3 from 1989-1993..
Engine available for this two kind of species as low as 1.3,1.5 injection or carburator DOHC@SOHC,1.6 injection or carburator SOHC@DOHC and 1.8 Injection or turbo know as B8Turbo and categories as BP(NA),BPT(180hp turbo) and BPD210hp turbo)
Ford Laser TX3 is using same code engine "BP"same technology as BPT.If u wanna rojak,still can.Some of mazda model also came with BP engine.Usually people that own TX3 doesn't have any "sakit kepala" to convert BPT(180hp) or BPD(210hp) bcoz just plug n play..
After the year 1993 and above (1994-1998) they were called BH,BJ or for Ford KJ..
p/s:Correct me if i'm wrong..