My 2012 xB gets really dirty at the back whenever I drive in wet & dirty weather; rain, snow, slush. I've had flat-backed cars before, (wagons, RAV4) but none seemed to get so dirty, so fast. Does the aftermarket or Scion rear spoiler cut down on any of this? Anything else that works?

Geezer

 

Its the nature of the beast. Likely due to the wheels back design & like you said the flat back.
Theres likely a swirling air mass behind the XB that is depositing all that road mess

Just added the spoiler & has no effect on this issue. Every XB should have the spoiler. Really adds to the "Look"

 

^This.

 

I recently added the OEM mud flaps to my xb and the rear window doesn't get as dirty. Normally it would be covered in dirt and salt, but the past few days its stayed pretty clean.

 

i just bought a wrecked 2006 scion xb in an auction it said runs and drives but it didn't. i first taught that was the exterior fuse box because it was broken but after replacing the broken relays it still didn't run. it only cranks. can somebody help me please. the battery didn't work either and i already replaced it.

 

I got the spoiler installed after having my 2014 xB for about 4 months. It seems to have lessened the amount of dirt that accumulates on the rear bumper. I definitely recommend the spoiler, it makes the back look sporty and less like a minivan. It is your best bang for the buck of the accessories.