As stated by others here, the RioCar (mark 2a) shouldn't suffer the negative spike problem that the Saturn cars have (at least my 2000 SL2 did).

The one issue that you may run into is the keyless remote will not work when the empeg is either powered on or in standby. I need to dig up information on where the antenna is, to then possibly move it away from the empeg. A Saturn/empeg owner in Denver does not have this problem, but he has a 2000 L series sedan that has a very different dash.