Do not attempt to park at the co-ordinates given as they are not for the cache but for a motorway junction on the M25 which you may or may not be able to see from the cache site.
When you find the cache the views to the North are far reaching and on a good day you can see the Wembley Arch and Canary Wharf. It is possible thought that you may prefer the views to the south where, on that same good day, the South Downs can be seen.
The cache can be found at N51 16.ABC W000 07 DEF
The values of ABCDEF can be found by solving the following puzzle.
5b1r3b2y4b2o5b2r6b1y3b2o3b
2b1o2b1o3b1y4b1r2b1r3b1o2b1o2b1y1b2y3b1r4b
4b1r3b1y5b1o2b1o3b1r2b1r4b1y3b1o5b
4b1o5b1y3b3r4b3o5b2y4b1r3b
3b1r5b3y5b1o6b1r3b1y4b1o5b
2b1o2b1o5b1y3b1r6b1o4b1y8b1r2b
2b4r2b4y2b2o5b2r4b4y3b2o3b
If the puzzle is not clear, unravel and start again.
You can check your answers for this puzzle on Geochecker.com.