Tutorial: Wide arches
Quite hard this one! Well, follow it by the rules, and it shouldn't be too hard for you.
       
 Wide Arches
 
Difficulty - ****
Standard arches ready for widening.  
Make a selection like on the left (using the Elliptical Marquee Tool (M), ensuring that you include the edges of the arch and the bottom of the tyre..

Select > Transform Selection to adjust the selection.

Grab the lasso tool.... andddd using the SHIFT key, select a bit of the tyre tread too!

 

Copy, paste and move the bloody thing outwards like so.....  

Delete any excess crap, and then switch to the background layer..

Grab the smudge tool* (R)and begin to click and drag like on the picture... Set the smudge tool to about 60% strength.

If you cant find it... its the 7th tool down on the left..

 

That it really. Really needs a front bumper adding, and some rims!

If you need to.. fix up the bumper line with the line tool.....

 

That's it really, the bottom half is ready for a bumper extension and some big big rims!!