I'm not familiar with your setup; is your intercooler under pressure (boost) or suction? If pressure then it appears the 90-degree metal tube to the right of your arrow is a good location. Just take it off and have someone weld a threaded bung to it.
Alternatively, what is the black thing sticking out of your intercooler? Can you take that out and thread a pressure sensor in?
2006 Lotus Exige: Avery Matte Graphite wrap, partial built motor (9:1 Mahle pistons, Ferrea Competition valves, ACT Clutch, ARP head studs), REV400, Nitron SAs, BOE QS exhaust, Ultradisc rotors, Moroso Oil pan, Circuitworks oil pump, CF Stuff (Cup Roof, ReVerie diffusor, side scoops, APR air dam, craftsquare mirrors), Worksbell quick release, Odyssey PC625, Morimoto Xenon HID, BOE Rear Oil Cooler, Difflow Aeroplates, BOE Swirl Pot, DaviesCraig EWP, Reversed Heater Matrix