Questions about replacing the chassis rails on RS2

[ColonialNomad]

I've posted this on the FB group so apologies if you've seen it already.

My RS2 needs the chassis rails replaced on the offside due to corrosion and previous damage.

The mechanic has provided the following parts numbers for the chassis rails 8A0803865LH and 8A0803295LH respectively. However I can't find any record of them on Audi Zap or Tradition catalogues to confirm price. Can anyone confirm that the mechanic has the right part numbers?

Also, what time and process is involved in the replacement job? The mechanic has quoted around three and a half thousand quid which I'm struggling to accept. On other cars like the Nissan GTR, it's a case of drilling out spot welds and plug welding. It seems like this mechanic wants to cut out a chunk of the underside that the rails are welded to rather than just the rails themselves. Can anyone advise if he might be overcooking the job?

Thanks in advance for your advice.

[SteveH]

items 5 and 6 on here?

https://audi.7zap.com/en/rdw/audi+80.../803-803030/#6

or are you talking about the sections under the floor?

[Tractor Dave]

Both available at Tradition 423 Euro each. Big job to replace properly me thinks