If you are going Pioneer I would get the
2-way 6855.

But, I have to admit I think three way coaxially mounted speakers are a joke.
IMO some may sound smooth but no where near accurate. 2 tweets and 2 woofers is all I need for my car to sound as good as my home system. Yeah, it cost the same too.

That's me, you may be differrent so I would listen to both speakers off axis as it would be in your car.