10 years ago my wife had a mk2.5 and we really enjoyed it , she got rid due to a change in her job ,now we want another just as a weekend car for a bit of fun . I’ve noticed on here there’s a big problem with rust on the front chassis I’ve looked at a few ,the first hadn’t been repaired and the rust was obvious and bad ! . The next two had been repaired but looked dodgy nearly all the chassis leg section had been plated up only the tops remained original metal . Are cars like this safe ,the vendors insisted it was a proper repair but it looked to much repair plate and not enough original to me ? I know there really cheap now but I wouldn’t want a dodgy one how can I tell if it ok ?
Will you put your money where your mouth is, like one owner on this forum did.
If you want to replace both the front chassis rails with original Mazda front chassis rails were are talking at least £2,500 and if they on the way out, probably looking at a further £2,000 in the next year or two for rear arches and sills.
Then at the age they are now, not unusual to replace the ecu / immobiliser unit as they can fail after 10 years or so, say 10% of the time but that is an easy say £150 fix.
Unless you are very keen, I would look for a very clean MK3, there are more of them about than very clean Mk2.5 cars.
In all cases, a ramp inspection is 100% required before buying the car,
Now this may be a stupid question but why would anybody want to replace the chassis rails with oe items? They have already proved to be of a bad design & possibly also poor quality steel.
Looked at several 2.5s now and I’m not going to bother there either rotten or bodged up ,going to try mk3 now but it seems they can rot badly as well 
The original design was flawed. There was a double skin in the centre of the chassis rail with a second piece of metal spot welded in place. This acts as a water trap and the section rots from the inside out at the base and sides. People initially did not know what to do about this so cars were scrapped or expensive repairs with new chassis rail fitment. Of course we all know what the problem is now and repairs are possible. At the time Scottishfiver fitted rails I don’t think repair panels were available. In any event the replacement chassis rails from Mazda would have been redeveloped back to a single skin and will doubtless outlast the car.
Hi
I have my 2.5 Sport for sale. Any inspection welcome. ( I have a scissor lift )
Sills done by previous owner at his local garage. Front chassis rails replaced by myself. I am a coded welder by trade.
Usual “Sport” stuff. VVT, 146bhp, 6 speed box, LSD, serviced discs/pads all round, oil changed every year, braided brake lines/fluid changed, etc.
Good soft top plus hard top, roll bar, leather heated seats.
103k
£1800
Paul G
Edit to add photo of repaired chassis rails
Repair panels that I’ve seen have m6 rivet nuts inserted. Mine has m8 flange nuts welded in. Panels 2mm thick.