Galvanic corrosion is caused by two dissimilar metals in electrical/physical contact with a corrosive electrolyte. In short, when aluminum and steel are touching each other in the presence of salt - there will be serious rust.
Road salt has always been a problem. Municipalities used to use salt crystals, but now many use a salt solution, which is even more invasive as a liquid.
British autos used to suffer from road salt. I had a new '59 Austin Healey begin to disintegrate in just two years in Minnesota because of the galvanic action between steel fenders and aluminum center panels. I cured the problem by isolating the contact between the panels with calk and weatherstripping.
You would think this is no longer a problem with the present-day aluminum bodied Jaguars. But, there has been a problem with some 2003-09 XJ6, which use an similar aluminum body. On these models corrosion has appeared around the boot lid, door pillars, door bottoms and wheel arches - see Jaguar World Monthly - Jan. 2013, page 31. It appears that the problem is the galvanized steel rivets, which should not cause galvanic action. However, galvanized coatings are not perfect. They can flake, particularly on impact, say during installation.
Jaguar may have addressed this problem using better rivet coatings or even larger aluminum rivets.
My point is a caution about driving your Jaguar on salted roads. Rust never sleeps....

 

I personally think that part of the article is flawed. The rivets were mainly used to build the chassis plus attached some of the fixed panels in place. When I did a factory tour and watched the X350 being built the seams on the doors, bonnets, boot etc are rolled, no rivets in sight in the areas that are reported as having corrosion issues.

If galvanic action caused by rivets was the issues all X350's would be corroding but it only appears to be happening in countries that use salt on the road over winter. My 2004 X350 started life in Japan then spent another three years in New Zealand and, when I sold it, it was as it left the factory, even the underside.

The only X350 I have seen with corrosion in NZ was on a recent facelift UK import and that was only on the boot lid where a chrome strip sandwiched between the boot top and face had been rubbing so I think exposed aluminium caused by stone chips etc being attacked by salt is the real issue.

There are also two welded seams on the A and C pillars that caused issues but that is easily remedied.

 

I think I should respond to the above assertion that the article I quoted may be flawed because the writer personally did not note such rivets in a factory tour; and never experienced corrosion in NZ.
The article was hosted by a well-respected Jaguar non-factory specialist; and there was no reason or incentive for him to say : "Surprisingly, the X350 is prone to corrosion around the boot lid, door pillars, door bottoms and wheel arches...."
My point is and remains that as long as Jaguar uses steel galvanized rivets to bond aluminum (I can see rivet points around my shock towers, so I assume they are elsewhere) they are not impervious to salt water-induced corrosion. I am NOT saying or implying that Jaguars should not be driven in rain, ice where the roadways are NOT salted. Most jurisdictions do not use salt to clear ice, but if you live in such area you probably know about the corrosive qualities of road ice.

 

There were apparently 3,180 Henrob rivets used in the making of an X350 so they are indeed used in more places that the shock towers They also used 390 feet of adhesive bonding, 6.6 feet of MIG welds and 180 blind rivets.

The bonnet and boot though are assembled using structural adhesive and spot-clinching where one metal surface is physically clinched over the other in a series of joins similar in size to spot-welds. 78 clinch joints were supposedly used on the car.

The 'expert' is spot on with the list of areas that typically have corrosion issues but one would be hard pressed to find a rivet near any of those places.

If you haven't been on a factory tour, I can highly recommend it. Unfortunately they have stopped building the X350 now but you get to see the parts stamped from flat sheets of aluminium, each component joined to the next, riveted, welded and bonded together and slowly a recognisable body starts to appear. I shall be going on another factory tour in just over three weeks, hopefully to see the XK being built this time.

If you haven't read it, I can also recommend the Body & Paint Repair Manuals for the X350. They explain in depth about repairing the chassis and body of the X350, the different types of rivets, where they should be used, how to remove and replace them, how to do aluminium welding, how to do bonding etc.

Another interesting thing but not X350 related is a documentary made about the X351, in the Mega factories series. There is a lot of footage in that shot in the factory showing the process of making the new XJ.

 

Almost all the corrosion I have seen on these X350 cars is what is called "filiform" (or crevice), corrosion. The action relies on exclusion of oxygen, but presence of an electrolyte like salt solution. Unlike steel, aluminium quickly forms an oxide layer in the presence of oxygen that prevents further action, but when oxygen is not there, the salt acts with water and the aluminium to form aluminium hyudroxides and hydrogen gas. The concentration of the electrolyte at the corrosion site sets up an osmotic pressure across the paint layer, allowing water to pass through the paint and the corrosion to continue.

You can read all about it on the internet.

aluMATTER | Aluminium | Forms of Corrosion | Filliform Corrosion