I would say doing EP's while driving is definitely a great way to learn them, I still do it.
As for Instruments, they are a pain, however it gets easier. With your scan, you know that at least one instrument is going to be moving (this will be your compass during a turn or altimeter during a climb or descent). One instructor once told me that while that is happening, drop that instrument out of a rotation or two of your scan, reference it, and if it isn't close to your roll out heading/altitude, skip it again for a couple times then come back. When you are close to your roll out/level off, check it more frequently. It will start to come naturally. Also, when you chair fly, put that chart of the instrument panel they should have given you up on the wall in front of you and scan it while you talk yourself through the maneuvers. If you have a roommate in the program, start grilling each other out of the blue on EPs and maneuver procedures (such as while making dinner or in the drive through), each one you miss is a round you have to buy.
), quite worked well for me because I tried to add real world distractions in my head and I need to concentrate to come up with as many scenarios as possible. I definently see the benefit of adding distractions for some people, though.
*sigh* .... sometimes, I love you boys. 
