OK, so I do mainly youth and vets, and for youth the CAR is typically a parent or coach (and more often than not, a coach, as trying to get parents to help for some clubs is nigh on impossible). For vets, a sub, but obviously of the more mature variety. 99% of the time no issues, other than where they don't fully understand the law - but on those occasions, as per the briefing I give them, acknowledge the flag and play on. In fact, most of the complaints are from their own team when they don't flag for offside. I will also blow for an offside I've spotted even if the flag hasn't gone up. The most complaints I hear about CAR's are normally directed at myself when I'm doing that role for my club, where coaches/parents clearly don't understand the law, e.g. "How can he be offside, he's in his own half" has been screamed at me at a number of games, even when I'm doing the hand-signal for, and shouting to the ref after he's blown, "coming back from an offside position". Where I have overruled a CAR, at the end of the half I will then explain why I overrode their decision, and only once have we agreed (politely) to disagree. Sad referee that I am, I even produced a guide called "Running The Line", which I hand out if a CAR has very little experience. So on the whole, they are well intentioned honest individuals wanting to help their club/team out; they may not be brilliant - today - but those that regularly do the role definitely improve, and I feel get a sense of reward from becoming involved (ie those that volunteer, rather than being volunteered). Long live CARs and them giving offsides.