[jQuery] Adding to a group of Radio buttons

These are the radio buttons on my form Honda Toyota Mazda Using jquery how can I add another selection to the list? Something like $label.append(' Ford'); ? I can't figure out the syntax. Any help please. Thanks

[jQuery] Form manipulation - Advanced

I'm new to jquery but I have no idea how to do this. Any help would be greatly appreciated and would lead down the correct path. Thank you in advance. There's 2 sections in my form. 1) Vehicle Makes Basically, I want the user to be able to enter their make if it's not in the list. Once the user