Is this something you brought to the dealer's attention while the car was still under warranty? If so, you could try calling BMW directly and complain that this was something that should have been fixed at the time it was first reported to the dealer, but wasn't. There have been cases where BMW at least paid for part of an out of warranty repair in cases like that. You could also ask for the part number(s) of the needed parts, and see if you can source them for less from a car salvage company as well. A few of the bigger salvage companies have quite a few BMW i3 parts listed on eBay, and can be contacted for specific parts.Any suggestions?
https://www.ebay.com/itm/2015-BMW-i3-St ... 0005.m1851