Your son might love this:
http://www.toysrus.com/product/index...ductId=2329760
My nephew has had his for a few weeks and he absolutely loves it. I was reading the comments about it and some people have had no problems with it, and others have had theirs fall apart, so I guess it's a case of buyer beware, or maybe it depends upon the age of the child and how they use it. My nephew treats his as if it was an actual tool - holds it properly and plays with it as if it was actually trimming the grass.
Re the YouTube videos - there's a lot of dump truck action on there too. That's another fascination of his.
