A garage should quote “worst” case, which will be sill, wheel arch and paint. Frequently the welding and paint will be done by seperate workshops, and that ends making the job take much longer.
Prices are generally rising, but I suppose a good “sill” repair (in reality, the rear section covering the jacking points to the seam under the door), ie. cut back outer skin, repairs to internal skin, new endplate, repairs, if any, to floor, supply and fit repair panel, finish, paint and stone chip (possibly re-stone chip entire side to get an even texture finish); £4-500 per side. In most cases, the inner sill can be repaired with scrap steel, but if the jacking point is too far gone (if its weakened, the jacking point lip will be turning inwards), possibly new Mazda parts are needed, adding £100-150. If the arch is needed as well (and arches can look completely solid until you start picking them back to find the inner arch has crumbled), another 200-300. I’m of the opinion that the rusting starts when the arch lip seal between inner and outer fails. If you fix the sill, not too far in the distant future, you will also need to get the arch done. Repair panels that include the arch aren’t much more than the sill panel, and you will get a better finish with a complete quarter repaint than just the sill area.
On this S-Limited I had, the jacking point had gone:
The repairer was able to make up a new piece
On the other side, new arch and sill
The repair you see to the inner wing is the result of what looked to be old accident damage in Japan; a ding, the panel had been pulled out and filled/painted, but accelerated rusting in the area, because the dent had created a rust trap.
Just a few years earlier, before my ownership, the car had been a trophy winning show car.
On my 1996 S-Spec, there was bubbling on the drivers side, and I had the car booked in for sill and arch. I kind of new what to expect, as a few years earlier, I had a “cosmetic” repair done. I decided to attack the area with a wire brush to see how much metal was left. It was horrific.
A suspicious looking small (0.5cm long) bubble on the arch was attack. As I expected, this opened up into a hole
On the other side, there was an old plated repair to the sill; to be honest, it all felt very solid, and I thought the small bleb in this case was surface rust on the repair. But once cust back, the repairer remarked he actually had to do more work to that side than the drivers side. I think the old repair made things worse.
