Manual says not to......
Piece of useful info since the smart is made much like my Suzuki sport rocket
I used a DIY car wash pressure hose from the
car wash down the road to wash down the 1000S a few summers ago..... from about 4 feet I pointed an pulled the trigger.....
To my horror

the water bounced of the front fairing and PEELED off about a half dollar sized chunk of my paint.....
Anyone who rides knows riders keep their bikes mint.... I was mortified.....
Cheers