slight problem with perspective drawing (i hope)

[cucaracha]

Hi,

I wanted to draw a perspective of a car like Scott Robertson :)
I have to say, this is my first attempt to draw in a correct perspective, so the question might sound stupid to you...
But now the problem itself:

I have problems to mirror a single area on the car:

http://www.epm-clan.org/cv/car.gif

So, as you could see, I don't know how to choose the size of it at the other side.
It's no problem to mirror its height (I drew helplines) but its width.
I hope you understand my problem, because my english isn't the best :)
cu,

cucaracha

[cucaracha]

ok the problem seems to be a bit too slight

- but i already found a method

[sic1]

It's good to know you resolved it, but uh - How did you resolve it? Maybe the solution can help someone else :)

Like uh, me, I have tons of issues... lol :)

[cucaracha]

there a different ways...

one's by scott robertson, for example:

http://www.drawthrough.com/images/tutorials/fb_step_5.jpg

the whole tutorial is on http://www.drawthrough.com/tutorials/perspectives.html (i hope it's ok that i paste it here)

another method is to calculate it via sinus or tangens-functions (don't know if it's the right word in english).
you simply draw a triangle with the vanishing points trough guidelines, then calculate the correct angles etc ;) my father tried to explain it to me, but i did it with scott's method :D