I have a '95 celebration and had noticed some bubbling but had not bothered until I read the article...so I did some digging
What a surprise - the engine side had some rust which was easily cleaned off - but the wheel arch side was more interesting. At first it appeared there was no rust - then I started scraping the rubberised bitumen off and wow, the rust was creeping down underneath. When I had finished, I had a 6 inch gash of rust that was growing hidden. I am pleased I did this because another couple of years and I would be as the pictures in Bob's article.
As Bob suggestes check it out - I was surprised at how hidden it was. While you are under the wheel arch check your damper top mounts - mine were beginning to rust there too...where does it end!
I have not got to the front sub frame yet - waiting until the summer for this one.