So, I don't see the problem. Perhaps you need to break down the problem into smaller more manageable steps. ;)
If I understand correctly what's wrong with using an array of structs here?
For one, my method of thinking means that the array will have to hold both integers and char arrays at once.
Why is this troublesome?
For two, updating specific areas of the Linked List is troublesome when doing the same with an array.
Again, just break these down into smaller steps write your function to handle the linked list and then write a function to handle the array.
It sounds like you already have the double linked list mostly done:
Try writing some code and when you get stuck come on back!
I also want you to maintain your linked list a little different than last time, you are still going to have a doubly linked list...
If you have already done a double linked list I don't get how you could be confused on an array?
and saves them both in an array (of car structure) and in a linked list.