Every year, Märklin offers a ‘Museum Car’ (DE: ‘Museumswagen’) for H0, Z and 1 scale, and those models are only available at the ‘Märklin Erlebniswelt‘.
In the presentation video of this year’s event, a possible Museum car for LGB is shown very shortly. It is a flat car with a wooden crate with “Bühler” print. Bühler is the manufacturer of industrial motors, and as you might know, these motors are used in LGB models as well. I cannot find any official information about the Museum Car, so a screenshot of the video will have to do for now:
[Update 10/01/2015] The Museum Car will be available for € 139,95, with Article-No. 40023.
Source: Märklin Museumswagen