How much rust is too much?

[ahlam1399]

http://img-s-msn-com.akamaized.net/tenant/amp/entityid/AApeDuq.img?h=100&w=100&m=6&q=60&o=f&l=f&x=1644&y=868Metal rot is ugly, but sometimes it can mean your car is also a danger on the road

أكثر... (http://www.msn.com/en-ca/autos/ownership/your-corner-wrench-how-much-rust-is-too-much/ar-AApewoE?srcref=rss)