Today I finally found the opportunity to try out the i3's built in trim rack! (Bet you didn't know this comes as standard equipment on all i3s!)
...actually I needed three 8-foot lengths but the guy in the warehouse said he'd give me the mangled 12-footer and 11-footer pieces in trade for not cutting them. Cool with me I said -- my car has a rack!
2 0 1 7 B M W i 3 9 4 A h B E V - O a k l a n d Wokeby Trunk Extension | Duosida 16A L1 EVSE SeaSucker Monkey Bar Roof Rack
I fitted 10 bags of heavy moist hardwood flower bed mulch in mine. I weighed one at home and it was 48#. I thought I could stack them neatly, but they are like handling a limp body and went in pretty helter-skelter. One ended up in the passenger seat.
The car felt really heavy, but handled the load very well.