Heimlichfan, it makes sense that southwest's deal would be good for you if you don't want the dining plan...you're taking away ~$230 for park passes (depending on how many days you're going/base or park hopper/etc) since it's buy 1-get 1. Then you're adding ~$250 for flight for one person (but ONLY one person, as opposed to 2, since it's buy 1-get 1). Those two things pretty much balance and then you're adding a bit more on for the car. So Southwest's deal works well in your situation.
I've been playing around with it and I just can't make it work out for me...but it can be good for some people, depending on the case.
You can change the number of days of the ticket...I don't have it open in front of me right now, but off the top of my head you click "remove" on the park hopper ticket thing, and then it gives you a warning about you need tickets for this deal...tell it to proceed anyways. Then up-top on the price breakdown page there is an icon for "add-ins". Click on that, and then on the drop-down box narrow your results by "Disney tickets". Then you'll be able to select a shorter amount of days, or add on the dining plan, or change from park hopper to base, etc. (Though if you add the dining plan and don't add tickets, you'll get a phone call because you can't do that). Why they made it this complicated to change, I'll never know.
Also, you can't buy less than a 3 day pass, which is why I can't make this deal work for me - I only want a 1-day.
From what I am hearing/reading, there is no reduced rate available for kids - so if you have kids, this probably doesn't work out well. It might, if you have expensive airfare and you don't want the dining plan, since kids park tickets aren't THAT much cheaper than adults...but it would be close.
You also can add
trip insurance through southwest if you want it, in this same add-ons section. I find it unlikely that you would be able to modify your existing disney reservation to get this deal, as one is booked through southwest vacations (a travel company, same as if you booked through
AAA) and one is booked through disney. You'd have to cancel your disney reservation (but you should still be able to get your deposit back depending on how far away your trip is) and then book a new trip through southwest and hope your room/category is still available.
Also, you CAN get
free dining through the southwest deal...but then you can't get the free ticket. (But you can still get the free airfare) So it all depends on how long you are going to be there/how many people are going as to which deal is better - buy 1 park ticket, get 1 park ticket free, or free dining. I think in most situations free dining works out better - but if you book through southwest you can still get one person's airfare free.
Sorry for the ramblings! I've been playing with southwest's website for 3 days trying to make this deal save me some money!