I think that Wheeljack is a special case, as it is kinda amusing to see an 'evil' Decepticon being made from a toy that originally featured tobacco sponsorship. Hasbro could also repaint it as the Decepticon Slicer, as that would be an easy homage to the G1 toy that was already a repaint of Wheeljack in the first place. Another redeco of the Wheeljack/Exhaust mould could also be released as Makeshift, who of course was the shape-shifting Decepticon from TF Prime who impersonated Wheeljack.

So I don't mind Autobot cars becoming Decepticons if there's a special reason for it (especially if there's an existing precedent for that character, as would be the case for Slicer and Makeshift). But otherwise I would prefer to see the Autobot car moulds being used to create new Autobots, as Ichikawa Hirofumi did w/ the eHobby retconned Diaclone reissues (Crosscut, Road Rage et al.).

Doing the coneheads then making more Seeker variants would be a preferable way to bolster the MP Decepticon ranks (as well as adding Bitstream and various other generic Seekers which have appeared in the G1 cartoon).

We know that redecos help TakTOM to make more money out of the mould and keep down the price of the toy. So what would be people's suggestions for repaint/retools of the Autobot cars without an obvious alternative? (e.g. MP Trailbreaker would obviously be redecoed as Hoist).

My recommendations would be...
+ Hound <--- Detritus
+ Mirage <--- Electro Disruptor Mirage (i.e. clear plastic)
+ Skids <--- Cross Cut
+ Tracks <--- Road Rage
+ Grapple/Inferno <--- Load Hauler
+ Sunstreaker <--- red Diaclone colours as new character, police car variant as new character.

But what about Jazz? Other than a G2 version (which would most likely be limited like G2 Lambor), I can't think of any obvious repaint potential.