I fitted some to boat locker lids. You need to do a bit of geometry to decide the open/closed lengths that you need, and then you've got to find what force is needed to hold the bonnet up at the point you want to mount the bonnet end of the strut. Then go strut hunting for one that has about the right force available and adjust your mount position in or out to compensate. It's not simple and you will slam the bonnet on your head a few times as you play with the adjustment... I found that a local Mercedes dealer had the best prices oddly enough.