The Sólheimasandur Plane Crash site is a location popular with photographers in Iceland, not far from Vik. Set on a black sand beach a good mile from the main Route 1 road it's not signposted and you can't see it as you drive along. To get there you need the very specific photo directions which you can find here. These were the directions we followed with no problems. The sign as you approach recommends 4x4 vehicles only but the sand is pretty compacted, in fact it's more like gravel and it can be accessed with caution and slow speed with a normal car - but I wouldn't try that in darkness as there some big potholes.
We visited in November and the light was a bit of a mare, but nevertheless is was a great site to visit, a real 'when are you going to get the chance to see a wreck like this again' moment. The site is a good 2.5 hour drive from Reykjavik but you can break up the trip stopping at Seljalandsfoss & Skógafoss waterfalls en route and drive on to 10 minutes to Vik and it's black sand beaches and basalt stacks (photos of all these to come).