I gave up and switched our sprayer over to our 55 a couple weeks ago and sprayed a couple hundred acres of corn there was no way a self propelled sprayer would have got through, some of it was so muddy I could hardly walk through it.  I also used it to sidedress 300 acres of corn in mud where the liquid applicator would leave 12" deep ruts in places and the tractor was just leaving lug marks.  The thing to remember is that if you do get the 45 stuck your going to need a long cable or strap to pull it out cause nothing with tires is going to get close to it.  The first spring we had our 55 I got too close to a spring along a water way working ground and I was able to get out but I pushed mud with the suitcase weights in the process and I've never mad ruts that deep before with anything.