any one got any good tips on what to use under the car to clean manily looking at back undre exhaust suspension arms that stuff ?????

As a basic start get an angled jetwash lance fitting. They also make life easier for wheel arches etc.
Exhaust wise I use autosol and steel wool

P21S Total Auto Wash or Meguiars Safe Degreaser and a selection of small bristle brushes for the cleaning step (coupled with high pressure water), then a tar & glue remover like Autosmart Tardis is often useful (degreasers don't always fully remove tar), then finally a selection of metal polishes to polish up bright parts. Blackfire's range is nice, as it features a heavy cut polish that quickly removes crud to leave a satin finish and a choice of finishing polishes to restore gloss. As Tim says, other good choices are Autosol ad Megs NXT, and 0000 grade wire wool can be useful. For really tough tasks, a Dremel is worth having! :)