Looks good, Only thing I would suggest is welding a gusset in between the tube and the plate. Reason being that with the plate laying horizontally like that, a hard forward impact could just bend the plate, may be something like this...
![](http://i493.photobucket.com/albums/rr296/twisted_yota/P1010479_Large.png)
I like that idea. good to have a second set of eyes.