Why is the animation not working?

Hi! I want to animate a geostruct (using mapping toolbox). Therefore i use the geoshow-function witch return an hggroup as graphics-object. The idea was to realize the animation by an hgtransform.

But it's not working. The point is shown by geoshow but is not moving to the left, as it has to do.

I'm getting a warning: "Warning: Struct field assignment overwrites a value with class "double". See MATLAB R14SP2 Release Notes, Assigning Nonstructure Variables As Structures Displays Warning, for details."

which comes up in the line

vec = geoshow(vehicle_pos, 'SymbolSpec', specVecpos);

Here's the Code:

    fig = figure;
  ax = gca;
  hold(ax, 'on');

specVecpos = makesymbolspec('Point',{'Default','Marker','o','MarkerSize',5,...
    'MarkerEdgeColor', 'cyan', 'MarkerFaceColor','cyan'});

lon_start = 10.89025;
lat_start = 52.41037;

lon_cur = lon_start;
lat_cur = lat_start;

vehicle_pos = struct('Geometry', 'Point', 'Lon', lon_start, 'Lat', lat_start, 'Id', 0);
vec = geoshow(vehicle_pos, 'SymbolSpec', specVecpos);
% hold off;
t = hgtransform('Parent',ax);
set(vec,'Parent',t);

for i = 1:100
    lon_cur = lon_cur - 0.1*lon_start;
    lat_cur = lat_cur - 0.1*lat_start;
    vehicle_pos.Lon = lon_cur;
    vehilce_pos.Lat = lat_cur;

      m = makehgtform('translate',lon_cur-lon_start,lat_cur-lat_start,0);
      t.Matrix = m;
      drawnow update;
      pause(0.5)
  end