Yeah, I have a Magnaflow on my D-Ram. Its good !!
The current exhaust system is quiet on the IS350. I would like to hear a little rumble. Sometimes you can get It to growl just a little in 3rd gear. Like merging into traffic on the super slab.
Yeah if I had money to burn, I would cut the pipes right before they go into the muffler. Then take the stock muffler and match to a close size Flowmaster model 40. Any of you motorheads should already know that the model 40 is a quasi-race muffler. Weld the hangers in place on the flowmaster like the stock muffler, clamp on the pipes same place as the stock mufflers.
Just install them on temporary. Then I bet you will hear something! My wife would probably shoot me as I come up the driveway.
How long is the exhaust system in the IS350? I read somewhere that when your in the 67-68 inch range you could get a drone at a certain RPM.
With the mufflers right on the rear of the car like they are you can try many possibilities. Summit racing, http://www.summitracing.com/ has a large selection of exhaust kits and individual parts.
Anyhoo, just rambling a little I'll wait and see what Borla comes out with since HKS dropped out.

 

So HKS dropped out completely? I thought they just weren't doing an factory option.

And is there any word on Borla's release date?

 

DanIS350:
Your probably right. HKS just dropped the factory option. My bad .

 

its too bad the only bolt on application is a resonator back, being theres no flanges after the cats, only after the resonator, i guess this is axle back also