good screws to secure amps to trunk bulkhead

[hugh jass]

this may be sort of an odd questions, but can anyone recommend a particular type of screw or bolt to use to mount amps or amp racks to the trunk bulkhead? i've got drywall screws, but that just doesn't seem like the right fastener for the job.
what about just drilling holes and using conventional nuts and bolts?
anyone use sheetmetal screws that they cut off on the inside of the bulkhead?
just looking for ideas. thanks.

[KenC]

Self-tapping metal screws... just make sure they're not too long.

[Mless5]

I always drill a hole and use a bolt with washers + locking nut with nylon insert.

[Mtriple]

I always drill a hole and use a bolt with washers + locking nut with nylon insert.

this.