Help re rust please!

Hi all and thanks for accepting me - appreciate it! I am distraught to find my beloved MX-5 has corrosion on cross members. My favourite mechanic tells me although he can fix it to sell it before mot expires (Dec,24). The car is 14 years old. I love it - its been a fantastic car and, apart from the rust, not a bit of trouble. Thoughts please…

Photos of the rust would help us gauge how bad it is!

My NC which is 14 years old also has signs of surface rust on the front and rear subframes but had it professionally cleaned and protected.

It passed the MOT fine and advisories for slight corrosion didn’t come back.

As stated already , get some detailed pics posted for the best advice moving forward .
They all suffer , mines a 2006 and I sorted myself.
A lot of man hours , sore back and aching joints but I’m happy it’s done.

Hope the pics landed…

I might be looking at the wrong part but both areas in your photos look like bolt on parts.

First pic looks like this part

Second pic looks like these parts

Hi thanks for your reply. Yes, from what mechanic said they are both bolt on parts, and apparently if corrosion is too bad the bolts can shear off when removing them. He says worst case scenario is new rear sub-frame…

Not sure about subframes needed ? the front brace mountings and one of the rear brace bolts , bolt into the floor panel ?

Thanks, appreciate the input. Is it worth repair would you say? Mechanic saying £2k if its a difficult job, and telling me to look for newer car from 2018 onwards - just not sure which way to go with this…

That almost sounds like “I don’t want the job - buy another car”

Do you have an MX5 specialist near you that could give you another opinion ?


He’s probably not far wrong with the worse case cost, and he won’t really know until he starts tearing into it. Beware of any garage giving a fixed price estimate.

There are some MX5 specialists whom I would say their skills are over stated.

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Thanks - again! He wants me to look for anr MX-5 no older than 2018 and expect to pay £15-16K for it. I am really reluctant to do that - for a start I dont need to drive every day now as I live close to work. It seems a lot to spend when the car I have is in good condition apart from the corrosion. Reckon I’ll get it fixed…

The Front and two rear braces will cost no more than £300 for Mazda parts.
The front brace is available from mx5 parts in aluminium which won’t rust for £110 approx , none Mazda rear braces online around £70.
The underside of the car will need assessing for further rust , especially rear arches under the liners.
The rear subframe will probably have surface rust at least which can be treated.
Plenty of threads on forum to read regarding the above mentioned.

Thank you! Really appreciate your help with this - need to decide now; sell as is and probably lose couple of thousand or get it fixed and maybe still end up selling a year or so down the line… appreciate all of your input guys!

As I said, until they start taking bits off, the extent of rust is difficult to gauge. NCs tend to rust “extensively”.

Thanks to everyone for their advice- so much appreciate it! Now ive swung the other way and think ill sell it. Going to try and post couple of pics that wouldn’t upload a few days ago…Processing: 1000009902.jpg…