guys just to pre-warn you fitting a light-weight battery/lower amp rating in this car causes issues imo..... ive had one for a while.... yes i know it doesnt get lots of use but its kept on trickle charge when not in use, but im just being honest and giving my feedback, the car needs to be registered to the "new" battery you choose, the z4m has a smart alternator that stops charging @ a certain level, this is set via the registering process ive already mentioned, otherwise our car will be overcharging your new lightweight smaller battery...... ask me how i know????? if you can get a battery with the same output your cool, but find one with a lower rating your car will be overcharging it and frying it......
The stock AGM batteries are expensive but very good when kept charged up, they cant leak and are commonly used in the marine industry due to their sturdy nature, they can also take being discharged and still be charged up and used fine..... They are very good batteries imo.. and in this case i personally would stick to the stock item, hell my stock agm battery is still in my garage showing a solid charge after all these years (kept on trickle charge)......
if anyone doubts what i say drop EAS tuning a line and they will tell you exactly the same as i have, they supply lightweight battery enclosures and braille batteries specifically for the z4m.
If the bosch item is the same rating as the stock unit, no issues, its just units with a lower rating, usually "lightweight" items.
Liverpool
