Add a new column type "AutoExpand", I have lots of grids where the number of columns changes dynamically but the width of each column is fixed, this means that the width of the grid data section changes and with only a few columns defined leave a big vertical space between the last data column and the grid right hand border.
It would be great to be able to add a AutoExpand column as the last column in the grid to fill any remaining space between the end of the last data column and the grid righthand border. This will give you a consistant look regardless of how many columns are added.