Just bought a 2002 toyota and intending to hang onto it for 4/5 years.
However there must be about 1/2 a kilo of mud, sitting in each rear wheel arch, behind the plastic covers.

Should I hose it out and replace with expanding foam, whilst it’s still summer & bone dry, or would the foam just end up trapping even more water next winter

high density closed cell foam = good idea. – infact BMW put it out there as a fix for subframe cracking in the rear of some of their vehicles. BUT its prohibitively expensive to do in terms of equipment and materials….

shit your find in BNQ in a spray can – bad idea – as itll not cure propper , wont spread proper and high chance youll find pockets of moisture trapped in corroding away your body work. Been tried countless times on land rover chassis.

Your best bet would be to strip it back , clean it out get all the dirt out and then get it buzzweld W.A.R coated so the mud will still be there but not able to corrode as its well protected.

Many thanks Trail Rat

Never heard of that process or product before.
But it’s exactly what i am after…

Looks like I am doing it myself though as no application centres around NthLondon

just hose it out regularly!

Probably find it was 15yrs of mud you removed.

If you put it back, you won’t need to touch it for the next 5 yrs