I do hope that when/if Infinite becomes unshackled by last gen, 343 will look into explosions. In Infinite the vehicles just go poof, there is virtually no debris, flames, smoke or whatever.
It's crazy that Halo 3 (among others) is still miles ahead on this front. Not holding my breath though as both 4 and 5 were bad in this regard, doesn't seem to be 343's strength. Which is kinda weird as you'd think that it could all be ported over relatively easy considering Halo's been on the same engine since forever.
The ghost used to split up in several pieces, sometimes an additional part would overload. Scarabs would literally crackle and then burst wide open, I have seen a piece of debris squash a mongoose. Those are awesome.
Did we need the 'doomed' state effect in campaign? It's so ugly.