it's a bit more complicated, you have to consider total amount financed (i.e. down payment), rebate amount, any negative equity, any interest you can make with the money (4% savings account or better), all different things. you also have to consider if you plan to keep the car, as you often pay more in interest for the first few years of your car than off the principal and can end up more negative if you finance. i'm not saying that it's always better to take the 0% or the rebate, but like you said sometimes it does in fact work out better to take the rebate and you shouldn't just say "oooo 0% i'm in"

 

With an 820 beacon score...

 

USAA's best rate for a new auto is 6.2% (fixed).

Pentagon Federal CU (known to have very good rates) is at 5.49 these days.

Since Mitsubishi has brought back the 0% in various forms every few years it seems reasonable that they would do so in the future.