I have Boston Pro 6.5's in the front... I don't think it required major trimming but not sure since I didn't do the install.
And even with great door speakers, you will want that sub... trust me..
2000 Non-nav Silver TL
Accessories: metallic tint 20% all around, factory underbody, Inspire tails, WW flush mount spoiler, hyper white turn signals
Audio: Kenwood DDX7015 monitor/DVD player, Boston Pro 6.5's up front + PPI PC2300 amp, Boston RX67's in rear, JL 12"W3 sub + PG Tantrum 300.2 amp
Performance: Comptech exhaust, H&R Sport springs, 18" 5Zigen Hyper 5ZR + 225/40/18 Yokohama Parada Spec 2's, Rotora slotted rotors and Axxis Ultimate pads all around, SPC rear camber kit
Security: Viper 500 ESP alarm