Trouble is people died way too often when WRC was like this.
Modern WRC cars are producing around 340bhp, the Metro was a tad over 400bhp in full works spec IIRC. I doubt that would make any impact on spectator deaths now that they have stopped the daft sods from camping out on the run offs of any remotely dangerous bends.
Safety has come a long way since, you won't get driver deaths like last time.
And you know that because your either:
a) an FIA approved WRC crash expert
b) taking a wild guess
There has been deaths in rallying from drivers/co-drivers since Group B was banned.
Unfortunately, you can add all the safety defences you want into a rally car but there will always be occasions when hitting certain objects will be fatal. I'd rather have a group of live hero's than dead ones.