Hi all.

I normally load my car up once a week with a lot of gear and the back end go's down a bit.

Is it worth putting some stronger springs on the help with the load.

Thanks

cheaper would be getting spring assisters. If you got stronger springs you'd idealy need to change the fronts too

spring assisters never heard of them.

How much are they.

excuse my ignorance but what do they do and how hard are they to fit.

I don't see what issue you're trying to fix?  heavy load, car sits a little lower at the rear, take the load out and it returns to where it was - ie the car is working as designed? 

Yes it's dose sit lower but to the extent that I can't go over any speeds bumps without the car scraping the under side. Plus I live on a small unadopted side street and need to use the small kerb to turn around.

Normally it is ok if I go slowly but when loaded the back end scraps every time. Just wanted to know if I can do anything ti stop or help this from happening.

Well when I say speed bumps the really small ones are ok but there are a few in my area which are a tad bigger than most which I have to avoid when loaded up.