Car Parking at Sixfields used to be easy, unfortunately the developers have got to the area and what was open land is now an all-shopping, all-eating complex and they don't care too much for the football fan.
You need to arrive early to find a space in the designated South Car Park at the ground. Otherwise it's strret parking and a fair walk.
The pubs on the Sixfields site don't like fans wearing away colours, and if you do get in they are incredibly busy on match days. Those arriving by train have the best choice as there is a good selection of pubs by the station and in the town centre.
What we seaid about pubs above goes for food as well, though you do have the cjoice of the usual mobile food stalls that spring up on match days.