I went to Auto Zone to get some Bosch filters today for the Solstice, they were on sale 2 for $10. I decided to look in the box. These are NOT the Bosch filters I have been buying from Rock auto, they look exactly like the Delco filters. The older Bosch filters were made in Spain by Hengst, and were the same as the K&N I compared them side by side. I guess I will stick with the K&N, they are a bit more expensive at I think $8 or $9 bucks from Amazon but you can just look at them and see they are a better filter, I showed one to Dark Tech, they don't look anything like the others.