A nutsert is a wide rivet that has threads on the inside. It allows you to thread pieces of metal that would otherwise be to thin for the threads.
I think all Ti's will need nutserts. Some E36's already have threaded holes there, but most of them just have the holes for the nutserts.
If you use the BMW nutserts you really shouldn't have to drill. Just remove the undercoating by scraping it away. Sometimes it can be a pain and using the proper sized drill bit is needed.
If the kit didn't come with nutserts, which it should have for the price, you can buy AVK knurled nutserts which are better quality. That is what TcKline provided with my bar when I bought it. | 
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