some cable ties finished the job .
Please don't tell me that you are buying a Haibike!
I have gone through my fair share of mudguards over time.
My rear homemade Scud Launcher was the most effective rear mudguard to date, but being close fitting at the seat stay area, mud cannot get away. I am working on a design of rear mudguard though, which will be fairly close fitting, but has an addition, which will clear mud from the tyre, before it reaches the chain stay and bottom bracket area. I thought that I had it sussed, but hadn't taken into account compression and tyre movement. I'll get there.
Raised mudguards just get in the way, look crap, are vulnerable, and for my use, just become a pain, especially when trying to lift the bike over obstacles, tackling tight or overgrown tracks, or in the event of a fall when they either snap, work loose or twist. Frame crud catchers are next to useless, and make very little difference. I've tried them all.