RichPug306xsi- nice undercarriage :bow
I've had mixed results with steam cleaners. I have a DeLONGHI steam cleaner, but I hardly EVER bother getting it out. It DOES work pretty well for this sort of thing, though.
I used to have a fairly big, propane powered one that was good for really awful jobs, but a hassle and mess to use. And like the even bigger ones, it could do some damage.
The little hand-held ones didn't last for me, and the last one (Bissel, I think) burned me but good when it failed.
Like Bill D, my late father REALLY liked his Steam Buggy. Used it to clean all sorts of stuff. It might be a good, reasonable way to go for this sort of thing