What plans do you have for your Gen4?

What should be protected first then. I just thought the diffs looked most vulnerable?

If it's anything like the gen3 then the most vulnerable bits are the protrusion of the transfer box and more importantly the aluminiumiumiumiumiumium castings that mount it to the frame. After that the lower damper mounts can take damage as they are only pressed steel, same with the radius arm mounts to the frame they can be bent quite easily. It's also not unusual for the axle to radius arms bracket holes to become ovals. Obviously this depends on what you are doing with the car and how much mechanical sympathy you possess. Other than the transfer box mounts on Ermintrude being steel I haven't damaged any of the above items and I off road every day only quite gently. Others who only go off road at a quarry every couple of months can smash stuff to bits in a day. The thing is that you have to weigh the protection of the guards against the potential reduction in clearance, additional cost, additional weight and the additional difficulty in cleaning the underneath to prevent corrosion. In my 90 I had diff guards and then had to have the diff pans replaced because of the trapped mud rusting them through!

Thanks for in info, I still need to get underneath and have a proper look. All very different to a std fwd car.

What's the general opinion on whether to consider having the underside/cavities Dinitrol'd right from the start? Been wondering about taking my Gen4 straight from the Dealer, when I collect it, for a treatment.

As an MX5 driver, I'm already wary of how vulnerable Japanese cars can be to corrosion from British road conditions. Fortunately the '5 only ever ventures out of it's garage when it's a 'top-down day' (like we've been having recently), but never when there's even a slight sprinkling of salt still about on the roads. As the Jimny is going to be used especially when the weather is bad, it's going to get regular exposure to a whole cocktail of harsher stuff. Any thoughts on the virtues, or otherwise, of underseal protection?

I waxoyled mine from collection and with a bit of yearly maintenance it was only last year at a total of 8 years that I took the silly jetwash to it and properly reapplied it. Couple of bits were a little bit of surface rust but 95pc was perfect. Well worth the effort.

Some great advice here, appreciated.

Regarding the under body wax protection I'm sure i read Martin Milnes (forum owner) .... say that the new Jimny's dont require treatment because they have some sort of procedure done to them at the factory already. Hopefully he may chip in. I could be wrong though, but im sure i heard this.

If it turns out that it would be beneficial, it would certainly be first on my list of essentials.