Hey I didn't say the pump was bigger, just the strainers on the end of pumps were made with larger mesh. Here are photos of the two strainers (# 3 and # 12; left to right; MSRP $2.62 & $3.85) in the Realoem schematic. Below is the SIB 610109. And here is a link for the repair:
BMW330ci.net - Changing Your Windshield Washer Pump (Do-It-Yourself)