The war is over
Going by my own experience I'd say you'll be fine. We were at a wedding in the North last year on the 12th - a big Irish wedding, loads of Irish regs and not one of us had any trouble. I know how you feel, I have felt conscious up there before but as long as you are sticking to busy areas I'd imagine you wouldn't have any need to worry.
Its very unlikely you would come up against any problems I reckon. In saying that though there is always one lunatic that likes to keep the trouble going, simply for a bit of excitement I reckon. We were Xmas shopping in Enniskillen last Xmas and a man started shouting round the carpark about the "all the Southern C*nts here today" and how they should go back to wherever they came from (and a tirade of stuff). But I have no doubt that someone with a Northern Reg car could come up against the same stuff in the south, if they just happened to come accross the wrong eejit. I would go tomorrow and wouldn't worry about it.
You will be fine - the marches and so on aren't until Monday, and all the shops are open this year.
To be honest, while it would be lovely to say "no, you'll have no problems whatsoever" I would be a bit more cautious. Make sure that you know where you are going and how to get there. Also make sure you have plenty of fuel so you don't end up having to search for a re-fill off the beaten track somewhere and risk ending up in the wrong area. I think it is so saddening that people should have to prepare/take precautions like this even today in 2009 but definitely better safe than sorry. Things around the 12th are always so much more tense than any other time of year so best to be prepared and avoid any possibility of trouble.
i would agree with the last poster. but as long as you know where exactly you are going you would probably be fine.
i was in belfast 2 years ago with my husband and we went for a leisurely drive whcih we often do on a sunday. We drove into an area, where an orange march was assembling. We were blown at and flashed at and several lovely people gave us the two fingers. Rather pathetic and childish but they saw the Dublin reg. we did a u-turn and drove until we knew where we were going!!!
I dont bother going too far up North around the 12th. I still go to my local town which is 5 mins away or to Enniskillen/Armagh.
About 4years ago, my parents and I were coming home from shopping in Belfast the week before the 12th and we were pelted with rocks and wood.
We kept driving and we eventually met the police on the road. The policewoman who was on the road had a rock thrown at her and was hit straight in the head.
Its not every area and its not every person. Its just certain groups give everyone else a bad image. As somebody else said, just make sure you are full of fuel so you dont have to go searching around in areas you are unsure of.