My coolant/antifreeze was sitting just above the min mark so decided to top up. i went to Halfords and was looking at the readmixes but then   without realising bought concentrate and have topped it up to just under the max line with this....without mixing. Will this cause issues? I've read that using neat antifreeze is not good - can cause over heating and is highly corrosive, but given it was only a top up rather than whole system maybe I'm ok... any thoughts :-s its the vRS 2.0