Aim at the bottom of the wall (the seam between the wall and the floor). A grenade should also work, but I haven't tried.

This will save you between 10-15 seconds. Also, it's faster to take the car outside the house, as I do in the video, than to run back to an awaiting cab.

The problem is you do end up gaining three stars. I actually might not use a cab there in the future and just go straight pay and spray. For classic% you'd normally have a helicopter. A grenade does work, but i found it to be rng. Never thought about using a RPG. Nice find.

The room shot will give you two stars, the hall shot will give you three. Either way, you're not taking a cab once you get outside. You'll almost always be able to lose your two star wanted level without the pay n spray if you head south. I'm not so sure about a three star, that will require a test or two. Another thing is, you can look for a cab as you're waiting outsides the wanted area. The pay n spray can be used as a backup strat if you feel you're going to have a hard time losing your wanted level once you've made it as far south as the pay n spray is.