Sign up to Kudosprime and check out the active map where you can find Barn Finds, Radars, Speed Cameras, XP Boards and Fast Travel Boards.
Check and un-check your finds, fade the map for a better view, zoom in on the map and use the filter to find a specific find for You. This map does not contain Storm island yet (Only the Mainland) So what are you waiting for? Join up to Kudosprime Today. It’s free and easy to use.
If you have any questions about the website, just leave a reply! 
FH2 link broken on that site
Ok sorry about the link. Just google kudosprime and the second link is the one to follow. It should say this - (KudosPrime | KudosPrime.com). Clic k on it. At the top left hand side it should say “create account”. Follow the instructions and then once finished click on the F.Horizon 2 link on the top. Once you click on that, click on the square that says Signs/Barns. You should come up with the map of Horizon 2 and just follow the instructions on the bottom right and then go and find your signs! Have Fun! There is much more to check out at Kudosprime like car stats and rims.
The map can be viewed without creating an account or signing into anything: Forza Horizon 2 (X1) Signs, Barns, Radars Map | www.kudosprime.com
It can but im not sure that it will save your checklisted signs and barn finds if you are not signed up or logged in so if you wanted to view the map another day you would have to checklist the signs all over again.