Its a bit of a tough question mate, only you would know your financial circumstances best. That being said if you are having a tight time at the moment, it might be difficult to meet repayments in future. At this stage id be allowing for a 2% rate rise in the next 12 or so months. Tagging on a 30g car to your mortgage might not be the best move, it may be a better option to save save and save. Im only offering my opinion as a fellow person in similar circumstances, so take it with a grain of salt