Question about rust

[littleboyblues]

Hey there,

I dont post much cause im in the market of buying an e30. I live in canada and alot of the cars for sale have rust.

Now most of the rust is superficial and on doors and fenders, however my question is...can you tell when theres too much rust and its starting to  deteriorate the structure of the car. Where would i have to look to know if rigidity is at stake. Im not familiar with where the load bearing beams are in the car. Could someone point out which member should not have rust on them?

Remember im look at buying a car so i cant really tear up the carpet as the owner stands by and watches...

Thanks.

[Bl0mgren]

front and rear members.. study the picture

[littleboyblues]

Thanks!