if i were going to do what you wanted i would run some speaker wire under the dash to a single pole switch, i think you could just insert the wire under that senor and still have it go in. that way the car would think its day when the switch is on. and auto when off. for the drls i would find the high beam power or ground whichever is common and not controlled and run them both through a normally closed relay. then run the control side to an additional switch and you hit the switch it would open the relay and turn it off.
1998 Bonneville SSE
2007 Monte Carlo LT-KYB, Clarion, Polk audio, Kicker
1999 Yukon SLE-KYB, Air lift, Reese dual-cam, Tekonsha
1987 Firebird-355/th400-nothing stock