I've got a 99 with an automatic! I took the intake horn off just to clean it! The next day o drove 100 miles on the highway! At 80. At about 15 pounds the whole time no issues! Now the clamp on the boot by the horn slid down the tube! I put it back on and comes off again now it won't stay on no matter how tight!

 

sounds like time to upgrade boots and clamps.

I run spring clamps and silicone boots from vulcan performance purchased via DAP..

 

2x on upgrading the boots. Have a good look at the lower boots of the intercooler as well. They can rub on the fender and cause holes to form.

 

another reason for the silicone boots ..the rubber ones balloon out under too much boost and end up getting cut by that sharp fender corner.

 

I changed mine yesterday and the factory boots were cracked and worn. The new boots from DAP are much thicker look more durable.