I have partial leather package too. I used to use the meguires clean and condition wipes, just on the seats - even the vinyl part. Didn't hurt them - and I'd been using them for about a year until i recently swtiched to this stuff called blue magic.
Blue magic leather cleaner and conditioner, made by blue magic:
http://www.bluemagic.com/
it works great. I bought the cleaner + conditioner (2 bottle kit) for 10 bucks at Costco. Works soooo much better than the meguires wipes i was using before. The label says it is suitable for both leather and vinyl/plastic. I use it on the dash and other trim too. I have a tan interior. I highly recommend it.
Larez