Bob,
The 2204 would not be nearly the scope the 4000 automotive scopes are. The memory is small and it's 8bit instead of 12bit. It also won't work with the automotive software, if that matters. You can still use the test and measurement version. You would also be limited to 20v inputs instead of 100v. The 4000 series has ±50mv to ±100v in 11 ranges to the 2204 ±50 mV to ±20 V in 9 ranges. The 4000 series also has dual 80MHz ADCs and 32 megs of memory to the 2204 8K. The 4k scopes also have thermal fuse protection for the inputs.
You would need 20:1 attenuators, current probes, automotive test leads and many of the other accessories found in the automotive kit. When you start purchasing these separately, the cost adds up fast. The automotive kits may seem pricey but they are really the best value for what you want to do.
My advice is to hold out until you have the funds to get one of the automotive kits. For research and development, I would also consider the four channel essential.
_________________
Tom Roberts
(The Picotologist)
http://www.autonerdz.com skype: autonerdz
THE PicoScope Automotive Authority
In North America