LOL! 
Do the Ultrasonic (sonar) sensors emit any audible sound (like a fast PIP’ing sound), as they send out a ping, or are they silent?
…Im taking it the IR would be silent anyway.
Your project sounds similar to mine Cheater (based upon the Tri-Track chassis), however I also plan on fitting a Cam2+ Pan/Tilt turret.
The Tri-Track doesnt have any mounting holes for sensors, as the Chassis consists of 2 horizontal plates of Lexan, however i assume holes are pre-drilled for Sensor brackets?
Please let us know how you get on, will be interested to hear about your progress. 
You can hear the pinging - if you can hear 40khz that is.
Human hearing is 20khz at best. Its ultrasonic.
I was going to go for the drill and glue method.
Not pretty but it will work.
Cheers for the prompt reply Cheater.
My name is Steve and I am a Bat - so the ultrasonic pip might just pip me off after a while! …OK, thanks for clearing that up! So will sound “silent” for us humans.
Hmmm, using screws and glue sounds a permanent way of mounting sensors to this Chassis, however if you have to remove Sensors in the future (ie: change of plan / prove faulty) could get even more messy trying to remove them from the Lexan base! 
The tri-track base has cut outs for installing a servo in the front for panning.
It also has holes for the injection molded “base rotate” kit for panning larger sensor arrays. The tilt can be added with Servo Erector Set parts. 8)