Can you interchanger a bumper from a 1989 325is to a 1987 BMW 325e 2dr?

that depends. does your 325e have a aluminum bumper or a plastic bumper? if it has the aluminum bumper, you should order new bumper shocks for an post face-lift 87 model. post 8/87. the reason? the shocks that fit aluminum bumpers are very long, and if u attach a plastic bumper, it will stick out too far.

if the 325e has a plastic bumper, then everything will be as easy as detaching and re-attaching your bumper.