I like the idea of the radar being related to automated defences, it would make sense, as things like Integrated Air Defence Systems do things like slaving AA guns to a radar facility, and using the radar to coordinate AA fire, so why not do it with ground defences (and air, when it's implemented) in empires? I also quite like the idea of engies getting a small turret, it would act as a guard for confined spaces, rather than a sort of field gun which is what the current ones do.
I do like the idea of these instillations, except that it actually isn't too hard at all to set one up facing an enemy base. if VF's can and have often been set up opposite a seiged base, then it'll be very easy for attacking teams to set up the instillation and radar (for what will be basically the cost of a tank). Honestly, I only see a large anti vehicle weapon like this as a bonus for siegers. a better turret is not going to save a base under seige, getting out of your base and attacking the enemy is.
