Gonna need tin snips, vibration causes cracks. I lost 2 mufflers already on my 49cc chain drive lol. Maybe a soft material would be better like a lunchbag or something that has a velcro lid. Won't get as much air but a drillbit could aerate it more.
First, "that guy"(me) dremeled the bottom of the basket out(or you can use tin snips.) The hole will be juuuust big enough to fit over the engine....but, only if you take the air filter cover and filter off first! You might also want to remove red engine cover to prevent scratches.
Next, inside the trunk bag is a Plano ammo box, bolted(4) to the top of the Staton U-Channel.
The box comes in handy to secure all my tools, spare tubes, cable lock, pump, etc... Plus, the incognito ammo can is locked with a small master lock, preventing theft of everything inside.
Then, I drilled 4 holes through the trunk bag & dry box and secured the basket w/4 bolts and washers on both sides. If you look at the picture closely, you can see the nuts and bolts next to the clutch bell.
Lastly, I bought a cheap, plastic, flexible cutting board to make a lid(cut to shape), and attached with 2 zip ties for the hinges. The outer side(non-hinged side) has bungee cords keeping the lid securely in place.
If you can't find a cutting board, you can buy a .50c plastic binder from Staples or WallyWorld and cut to size.
This is probably my 5th or 6th iteration of this design. Hands down the best, and very stealthy.