I went to the MOLA download page you listed.....didn't know which to download, so
went into 3DEM, and selected an area that looked like it might be Olympus mons,
and noted the Lat/Long.

Then selected the .img  that included that area, downloaded it, and
then loaded it into 3DEM......then saved it as a USGS ASCII DEM, and imported/loaded
into VUE....but VUE crashes each time.