Well,

My application is automotive application. There could have about 30,000 parts per year.
The need is to locate the code into a flash in order to let the After-Sale team able to update the software with a laptop.
It offers also the way to design easily the code as it's always in development. Regulary, a software version is industrialized and it's only necessary to send the code to the provider. There is nearly an update per year.
When working for Renault VI and Mack-Trucks, in the past, the provider was VDO. The Electronic Control Unit I was project manager was built by this way and was using an Infineon C167.
You could think that an update per year is crazy, but in fact, the Electronic Control Unit is mounted on several kind of trucks and the software versions depends on the generation of the truck and its configuration. There was about 5 versions in field at the same date.
Thus, the development team is able to update itself the code in the trucks or integration platform to make tests...

Well, I've read from Peter that some parts may be interesting because they're IAP and are including a CAN controller.
Using EPROM for bootloader doesn't seem cost effective...
The Cygnal parts beloved by Michael may be interresting, I've to investigate to check if it could fit the need. JTAG isn't according to me really the answer to my issue, but.... it may offer some advantages.

The purpose of my thread was to know if someone had a global method on how to implement a code easily updatable in after-sale and allowing to use any microconroller, even if it's not IAP and havn't bootloader.


Regards
Stephane