Custom Fields dependencies

[e.arbitrio]

Hi,
i need to create 2 custom fields in vm 2 that are related between.
I've car accessories products and in every products i must specify the copmany (Dodge), the model (Viper), the Year (2008), the engine (8.0). A same product can be compatible for more car models so in a product i must insert more car and more models.

Hope it's clear!

How can i do?

Thnaks