Stock car squaring issue

we squared the car and it seems to think its square but it makes the strings(lines) on the side look like one is farther forward then the other.. we thought the rearend was twisted but we can't find any issue... we don't know what to *** the two lines on the side are the same but the crossing x makes the car lines like this:
               _________
back of car   ________       Front of car

Need help finding out what this means and how to fix it.. PLEASE HELP  

I was quite confused with it too...
Any help from other members please.. I wanted to know it too!

Kind Regards,
Julie from http://www.arabiandrift.com  
Never drive faster than your guardian angel can fly.

I'm confused as to why you don't use a real means of taking measurements. String is a quick way in the field, to reference but not to set-up your race car??

1.Your going to have to take REAL hard measurements.
2.With a good tape measure.Use the same measuring tools for all the measurements.
3.If you have different size tires on it it will measure different.
4.Don't use the sheet metal to take any measurements.
5.When you take these measurements give us a reference point of some kind. IE front of car rear of car. C/L of front spindle to C/L of the rear axle.
6.When you do that we'll help you.

What we have now now is nothing to go on.
Is it a dirt track, asphalt, or 1/4, 3/8ths mile what. I'll tell you I built my first race car with plumb bobs, T/square, rulers, and a lot of PATIENCE!!