I am just wondering if there is an aftermarket warranty company that supports cars over 100K Miles.

Warranty Direct. Check em out.

yes there are but the warranties are drive terrain related only. (Engine, transmission, differential)

There quie a few. I checked when i bought my 7 but decided aginst it. Im to much of a DIY and l like the feeling of accomplishment, when i look at my car i know im the reason it looks and runs so good.