How about the field artillery? Having the half-tracks tug around artillery cannons as they sometimes did. I believe the Allies used the 105mm Howitzer and I think the Axis did, too. And they still carried a MG with them.
<Edit> How about the carrying a 88mm gun, too? Sacrifice firepower for mobility and set up time. Also, how about it's like getting vehicle supplies. You stop takes 10-60sec to set the cannon up and then it's like a 5" ship gun. <Edit>