There's still this plausible theory that MH370 avoided being noticed by any radars by shadowing SIA68 on its way across India.
"Plausible" only in the sense that, in the absence of any firm evidence to the contrary, pretty well any hypothesis that anyone can dream up can't, strictly speaking, be ruled out.
That would of course also include the "flying for 6 hours with an onboard fire" and "abducted by aliens" scenarios, as well as the above.
