you're going to crack it if you hit it hard enough. but you'll need more then a mallet to fix... like sledgehammer.
ive had SSR's repaired here long time ago. they did great work.
Wheel Collision Center Bath PA- Excellence in Refinished/Used Factory OEM Aluminum Alloy Wheel Rim Sales & Alloy Wheel Rim Straightening Repair Refinishing & Recycling! - www.oemfactoryrimwheel.com Excellence in Refinished/Used Factory OEM Aluminum A
check your local bmw/benz dealers as well. they might have a contracted wheel repair shop.