I am so fed up forking out money to replace exhaust bits.

I have an AUII I6 with a 2'5" system & every 2 years without fail I need to replace either centre section or the tailpipe.
The most common issue is the independent flex between centre section & tailpipe, I fixed that long ago by simply welding a bit of steel on to link the centre muffler hanger with the tailpipe.
Stops the inevitable cracked muffler flange, but still the steel itself is stuffed in 2 years tops.

On this occasion the centre muffler baffle started rattling, then it blew a hole through the casing. zorst is 2 years old!
Hunted through some wreckers as a temp' solution, found a near new one but of course the centre muffler flange was already cracked. So no good chasing used zorts.

Stainless is a viable option but it comes at twice the price as stock, & even then no guarantees it will last more than 4 or 5 years.
So what's the solution here ?

I'm seriously considering making a cat back system from alloy pipe but I reckon I'd need heat shield almost the entire length of the system.
I'm a welder so I know all too well that alloy transfers heat rapidly, so apart from the ambient heat I'm also wondering if the alloy would be more prone to cracking under extreme heat conditions.

So is alloy a viable solution here ?

One other option that was mentioned to me years ago was to drill & tap in a grease nipple somewhere near the engine end of the exhaust.
A few squirts every month is supposed to stop the zorst from corroding from the inside out.
I feel this would work but my fear is that over time gunk would build up & inevitably cause a fire in the exhaust, or.... would the grease cook & slowly burn off just leaving sealed steel behind ?

Feed back welcomed here as this subject is long overdue for discussion.

Quite a lot of people coat the insides of their tail pipes and a bit further up with POR15 once it is treated it wont rust again ever it is really good stuff.
Try por15 web site.

Good advice although I'm not cool with their prices. RANEX would do a similar job & is half the price.
The main failure with exhaust systems in general is the muffler.
I'm there right now, so maybe just an alloy muffler box would rid me of the issue for a long while.

Still, I want to get away from steel altogether. Treated or stainless, still gonna fail.

I've had the car almost 9 years & in that time I've replaced the centre section & tailpipe at least 4 times, given the muffler flange was cracked when I bought the car.