My rear left window fell into my door last summer and the rear right a few weeks ago. Both have been taped up ever since, so I read up here and I thought it would be the broken window clip thing. I checked and the clips were fine on both windows. It turns out that the problem is in the window regulators. The piece of plastic that attaches to the bolt on the wire broke. Can I buy this plastic part somewhere or do I have to buy two new window regulators?