I also used a bag and one of my front tire & wheel assemblies. I had "The Bag Lady" make this custom one and she now has the pattern for them.
In the first photo is the spare, the jack ($15 from WalMart - GM Goodwrench), 1/2" breaker and socket from AutoZone and a low cost emergency kit that we gave out at our annual dinner this year.
Then I tucked it all in the bag - it fit great - THANKS Robyn.
I zipped it and it carried to the car very well.
I loaded it behind my seat and the jack box dropped down, but a weeks worth of groceries for two still fit. If I wanted max space I could use a plastic box for the jack & wrench and bungee cord it to the top of the tire.
My only concern for some of you is where you have your seat. I am 5' 8" and it fits perfect. But if I have the hub of the wheel forward I have a major, hard lumbar support. So I turn it around so the emergency bag is forward and it feels fine. But if I was 6' 4" it might not work.
Those that want something like this, search for The Bag Lady from NJ and she now has the pattern. It worked great and she was great to work with.