Kind of.. ideally you want atleast 1 installment loan reporting in order to maximise the fico scoring system.
As long as you have a separate installment loan reporting, it's okay to pay off the car(if you're wanting to max your fico score for right now - remember credit scores have no 'memory', so if you don't need your highest score RIGHT NOW, i.e. you're repairing credit to buy a house in a year, then maybe it'd be better to pay off the car now and open a SSL loan later on to check the installment loan off your list)