I received the MTC air duct boot yesterday and I ran into the same problem others have run into when buying the very cheap MTC replacement... it just doesn't fit right. The rubber appears to be of good quality but the lip on the rubber that is supposed to slip into the groove in the frame just doesn't make it into the groove all the way around. Specifically it doesn't quite make it into the groove on the end that is adjacent to the big opening that fits over the throttle body.
Here is a picture of the large opening I'm talking about. The red arrows are pointing to where the rubber boot just doesn't fit into the frame as it should.
The same areas on the other side of the boot (where you can't see) has the same problem. The lip on the rest of the boot fits the groove in the frame ok.
You can roll the lip around between your thumb and forefinger and expose the lip a little more, and then stretch the boot as far as you can while forcing the lip of the boot into the groove in the plate, but you need to stretch it so much that it just springs back when you remove the pressure from your fingers and the rubber springs back before you can attach the plate to the body of the air metering unit.
What I did to get around this problem was I attached the rubber to the plate and while holding pressure on the places where the rubber wanted to spring back, I inserted one of the attachment screws thru a fender washer and then screwed it to the plate which made the rubber lip captive in the groove by the fender washer. I did this in several places around the plate so that the rubber couldn't pull back and was held firmly in the stretched condition overnight.
The hope was that when I removed the fender washers the next day the rubber boot would remain in the grove while I bolted the plate to the air metering unit. It worked and I was able to secure the plate to the air metering unit with the rubber lip now being held captive between the plate and the air metering unit.
Here's another angle of the boot, plate and air metering unit.
It looks like the MTC replacement boot at $30 bucks just might work out fine.
The white stuff on the boot is powder... they ship the boot covered in powder in a plastic bag. I'm guessing it's to keep the rubber fresh until you get it bolted between the plate and the air metering unit.
The MTC replacement boot gets a thumbs up for the quality of the rubber but a thumbs down for fitment. With the one proviso of the fitment problem (which has a workaround) I'd say the MTC boot is a viable alternative to the much more expensive OEM products. Just be careful... there are many on FleaBay who will sell you a $30 MTC boot for $70.