I've been under many cars in my time and have found the underneath of Vauxhalls to have held up quite well. Comparing their underseal to a few manufacturers I'd say their underseal is thicker, more absorbant to impacts, tough and definitely is one of the best for protection against corrosion.

I'm just starting to get little bits of surface rust underneath my GX which I will fix but when I'm done want to underseal these areas and the rest.

Can anyone recommend a good underseal off the shelf or net that they have had experience with. One that can cope with the gritty spray hitting the inner arch?

Hi welcome, I've always used waxoil although the that pressure sprayer is a nightmare, last couple of years I've used the rattle cans for the bits I can't get with the brush and use the waxoil/hammerite underseal in a pot. Takes longer but I find the coverage and lack of mess outweigh the extra time.

This is most recent attempt

I previously used waxoil with the spray lance for areas under a car where there isn't much spray. Not sure how it would hold up in the arches.

is the pot stuff a bit more robust?

Thanks for the quick reply :)

Pics just through also! Looks such an improvement.

I found with the lance stuff it would wear off the arch within a year, plus I ended up with loads of overspray on the bits that got hot [emoji35]

if I'd had more light when I'd done the work in the pics above it would have been better but I've had a look this year and it's looking ok, they reckon it lasts 5 years.

Did the rear arches this year as had the shocks off anyway

Awesome. Thank you