Hey Tim! Welcome to SLKWorld!! Nice to see another 170!!!
Man! I wish I could give you some input on your sub-woofer challenge. I honestly have never seen anyone here do anything with a sub in the trunk because you already have subs behind the seats. Granted they aren't blasters, but they do the job considering how big (or small) they are.
Please share with us whatever you come up with.
And post some pics of your ride!