Any tips on traveling to Chile & Argentina?

A friend and I (two males in our mid 20's) are planning a trip to Chile & Argentina this summer (their winter) to go snowboarding and to travel the countries. We were going to rent a car once down there, but were told it would be a "safety issue" to do so. Does anybody have any experience?
We're both americans.

I lived over 5 years in Argentina. There are no "Safety" issues with renting a car other than the poor driving habits of other drivers and the mountain roads which you would be driving on. Whoever said this has never been there or spent maybe a week there.

The Cordillera from Bariloche to Mendoza and Santiago to Villarica - you have a 0% chance fo anyone doing any violent act to you. The car might get stolen while you're sleeping, though.

Check out this site :
http://www.chipsites.com/chile-travel/rent-a-car-tips.html

I'm a Texan, currently living in Argentina. BagOfSwag's answer is "right on". One little tip.... in "additional details", you said "we're both American". Don't say that to Argentines. It's arrogant and offensive to them, because they consider theirselves to be "American" also.... (south Americans). The correct description for your nationality in Spanish is "estadosunidense".

Have a good trip!

People don't get offended if you say that you are "American".
But, in Spanish, America is the whole continent, not a country.the Country is UNITED STATES of America.

Buenos aires is very european compared to any other city in Latin America. don't expect mariachis, and don't bother ordering tacos or salsa.
Food is great, pizzas, ice cream, beef and excellent pasta.
People are well educated, they are a wonderful mix of latin and european.
argentina is very affordable, many cultural sights to see, theatres and 24 hours bookstores.

Bariloche is wonderful, like Switzerland, lakes, snowy mountains, ski resorts.
Mendoza and Neuquen too, very charming, and the best wines of the country are there.

Just like in any other country, talk to locals, ask where is safe and where not. People are very friendly, and they'll try to make you feel at home.

Have a great trip!