The complete situation around Eisenach (Thuringia) has changed a lot during the years 2009 and 2011. A new motorway bypass for the A4/E40 has been built. The old A4 is now the new B7/B19/B 88 but not leading back to the autobahn A4 in eastern direction anymore. Some stretches have completely been dismantled. Older maps might not be showing the present situation correctly.
To reach LOMO Autohof Eisenach from the city center of Eisenach you can take bus number 1 to the 'Marktkauf' supermarket and shopping mall. Get off there and walk 10 minutes uphill to one of the many traffic lights on 'Mühlhäuser Straße'. It should not take more than minutes to find a (commuting) driver that can bring you to the 'LOMO Autohof' on A4. Build a cardboard sign indicating 'A4 / E 40' (or 'Autohof') on it. The Autohof is on one side of the autobahn situated for both directions, once you have reached it you do not need to change sides (east/west).
From the Eisenach LOMO Autohof you should be able to reach Erfurt (30 minutes), Jena (60 minutes) or Dresden (one hour and 30 minutes) in eastward direction as well as Kassel (60 minutes) or Frankfurt (one hour and 30 minutes) in westward direction.