I did a few of the missions in co op a few days ago and they're much easier. I'm not sure if the scores are the same as for solo play but or if they're double what they are but it seemed easier playing with 2 of us.
Although the destruction derby was just as impossible with every AI car coming for you and ignoring each other - and it seems the only way to win it is by destroying everyone yourself - but half of them kill themselves crashing into walls... or you'll destroy someone to the point they set on fire and randomly you'll get points for making them explode and another time you'll get sod all.
Very hit and miss
Although the destruction derby was just as impossible with every AI car coming for you and ignoring each other - and it seems the only way to win it is by destroying everyone yourself - but half of them kill themselves crashing into walls... or you'll destroy someone to the point they set on fire and randomly you'll get points for making them explode and another time you'll get sod all.
Very hit and miss