You will need the 8% deposit on whatever the purchase price (not valuation) on the property.
Lets just say the sale price ends up being €250,000 (just giving you an indication), you would need €20,000 deposit.
Obviously the correct and prudent thing to do is to save and payoff your car loan asap.
If its a case that you are going to get a mortgage irrespective of your car loan then you should save save save. At the moment you MIGHT be able to get up to around €310,000 (based on no car loan, figures calculated by AIB) which means that even with your car loan you might be good for €220,000. So in essence you have a better chance of getting a loan based on your savings (in this instance) as opposed to paying off your car loan.
This is not advice on what course of action you should take, this is simply laying out the way things appear to be for you based on the limited information you have provided.