I picked up a used arm from a 94 530I for $30 or $40 and just bolted it on. It took about 5 minutes. I did it a couple years ago, so I don't remember specifics but it was super easy. I have tried a couple different "hingeless wipers" and I like the Michelin Radius wipers the best. I buy them from Costco when ever they have a $2 off coupon. They're like $9 each.