How to make this drain better
Uniform Plumbing Code (UPC) has this to say about horizontal drain lines meeting other horizontal drain lines.


  706.3 Horizontal drainage lines connecting with other horizontal drainage lines shall enter through forty-five (45) degree (0.79 rad) wye branches, combination wye and one-eighth (1/8) bend branches, or other approved fittings of equivalent sweep.


So you'll have to use a 45 wye, or a combination wye &amp; 1/8. This configuration gets the water moving in the proper direction, before it's dumped into the other line. 


45 wye


Combination wye &amp; 1/8

You'll also want to avoid trying to make water go up hill. 



Go back to the original setup. Then...


Remove the 45&deg; fitting near the wall.
Come straight out of the wall, and install a 45&deg; wye.
Connect the trap on the right of the image, into the straight branch of the wye.
Connect the trap on the left of the image, into the angled branch of the 45&deg; wye. 



The red lines represent the 45&deg; wye fitting