Hi Playdo - Rhino does have a lot of various tools in it which are not in MoI, including some surfacing tools which could be of interest for automotive like more options for controlling surface continuity.

If you're looking for some kind of advanced surfacing functionality, then you'll probably want to use Rhino for some of those specific tools.

MoI is more of a streamlined and easy-to-use tool - it has a much lower learning curve and also some basic things like just regular curve drawing are more modern and fluid in MoI, which can translate into basic drawing operations happening more quickly and easily in MoI. So because of that some people like to use MoI and Rhino in combination with one another, you can do stuff like draw things in MoI and then move your model over to Rhino in order to use some of the more advanced tools over there. MoI and Rhino share the same file format and you can also just use Copy and Paste to move objects from one to the other.

If all you care about is a kind of checklist of individual features, then Rhino has a whole lot more of those. But if you take into account fluidity and the ease of use of basic operations, that's a much different picture with regards to MoI.

There are demo versions available for both, so you should spend some time experimenting with those. But one good way to go is to get both.

- Michael