Brayford Wharf North
This Nando's is about a 10 minute walk down the steep hills from the Castle and Cathedral. It's 100 yards or so from an Odeon. Lincoln Central Train Station is also in the city centre and half a mile walk from Nando's.
There seems to be a car park on just about every corner in Lincoln city centre - all of which accept cards and payment by phone. All vary in size, hourly/daily rate and some also have maximum stays. Generally speaking you'll pay about £1 an hour, up to £6 for all day, or £2.50 for evening only (6pm-8am). The Lucy Tower multi-storey is nearest to Nando's and just a hundred yards walk away.