Will this bolt straight onto my car with no modifications?

Yes. This mirror uses factory mounting points — no drilling or bracket fabrication needed. You'll bolt it on using existing holes on your door frame.

Does this come with the gasket or seal between the mirror and door?

Gasket or seal not specified in the assembly. Check your current mirror setup before install — you may reuse the existing gasket or source a replacement seal separately if needed.

What if the mirror glass is broken — can I replace just the glass?

This is a complete mirror assembly. If your current mirror has good glass but the housing is damaged, you can sometimes swap just the glass; check your existing mirror's design to see if it's serviceable before ordering.