I have these models like these

```
clients(id,name,address)
cars(id,platenum)
client_cars(clientid,carid)

```

What I would like to do is add `cars` to a `client` and the data would be saved to the `client_cars` table. Where the form to add the data would have checkboxes of plate numbers. Does anyone know any good examples that accomplish this kind of idea?