Forget about ASIL stuff and even dedicated mcu's if you're not doing some safety critical stuff.
Most OEM's will go for the cheapest hardware, so no specialized mcu's if they can. (let the software guys handle it ...)
The MPC / SPC series is nice if you don't have to write the Autosar MCAL drivers for it ...
A good debugger will be the difference between throwing the board out the window and understanding why the chip is doing something that makes no sense.
(like PLL's having the locked flag set, but behaving like wide band jamming devices, or having to set / clear a lot of undocumented bits / registers to make something work)
We used Lauterbach debuggers because they could be easily automated / integrated in the test env.
Also, the MCU definition files where text based, and you could easily patch them - extremely important for "cut 0" chips.
From my experience, you might have a lot more to learn / and show at an interview if:
- learn CAN / LIN / FLEXRAY, at leas CAN is easy / common and you can play with your vehicle, if you can get your hands on the CAN message database (or reverse engineer it)
- learn robust hardware design - how to protect inputs from noise / junk, how to detect that external hardware is missing or defective (a button or an indicator, for example)
- learn to design robust code - parameter checking, how to handle errors, how to perform runtime tests ( test RAM or some important sections at run-time, for example / run a chip-check in the bootloader section, perform safe firmware update - no bricking allowed )
- learn how to design the code to be easily testable (TDD - test driven development )
- learn how to build an automated testing system for software and hardware
- learn how to document everything - as in design requirements, breaking them down to different software and hardware blocks, down to component and line of code
- think about the FMEA ( failure mode analysis ) - what happens if the PLL does not lock, what happens if this CAN message has a bit field out of range, what happens if this pin goes open circuit, what happens if this variable is corrupted by the array that's next to it
- get comfortable with assembler, very low level debugging, memory maps, linker files, optimizing every possible byte or instruction
Once you are comfortable with those things on a platform, you can switch to something else quite easy.
You'll learn a lot if you run through all these steps with a normal MCU that has cheaply available tools.
=> get your project through all those steps with a cheap arm that has all of your peripherals, dirt-cheap dev. boards and it's supported by open source tools + has a good community around.
The step from avr to an arm will be a hard one, so it might be a good idea to start from 0 - set up build env., set up debugger, learn to connect them - some basic openocd stuff (recover a chip when you accidentally reconfigure the jtag pins for example), then learn how to work with that chip from 0 - write your own low level drivers, etc - that way you'll get used to the hardware, learn how to understand the documentation, and learn how to debug.
(not very articulated at this hour, but hopefully I got the idea across)