SupersGURPS Supers p. 84 discusses using Ally for super vehicles. To use these rules you pay for a base vehicle with wealth in some way, then write up that as a character. There are guidelines for converting a vehicle stat block to a character; which are a useful reference if you are converting a vehicle block to a character (or vice versa). This gets treated as a 0 point template (even if it isn't) for an Ally, with upgrades increasing the Ally point total.
"The Captain's Boat""The Captain's Boat" in Pyramid #3/71: Spaceships II has a system for converting dollar costs for vehicles to the Patron advantage and suggests doing the same thing for Ally in regards to space fighters and mecha.
PK's House Rules"Nipping Problem Allies in the Bud" on Jason "PK" Levine's MyGurps site has a number of changes to how nonsapient allies work (under "Nonsapient Allies on the Cheap"). Notably he suggests giving them a feature that makes IQ 0 point N/A traits.
Desolation RoadIn my last (non-DF) GURPS campaign, Desolation Road, the Peshang are a race of cat sized reptiloid aliens with SM -4 and ST -6 who very early in the setting's history once fought a war against invading humans by building "giant" SM 0 magical mecha (a deliberate subversion of Macross). In the actual campaign all the Peshang were descendants of the 453rd Dragoons, a military unit based around these Peshang Assault Constructs stranded on their last deployment when the interstellar gate network stopped working. Unable to build new constructs, the dragoons of the 453rd became a hereditary military order, like Battletech mechwarriors. In order to make ends meet the regiment became mercenary, and individual dragoons are permitted, even encouraged, to take contracts and even act as free agents (so long as they pay fees back to the regiment, never let regimental tech fall into other hands, and never fight other Peshang).
I needed a way for PC dragoons to pay points for their construct, since these things can't have a meaningful dollar cost in the setting (and any notional cost would be so artificially inflated that it would be out of reach for a Peshang officer with Comfortable Wealth). Therefore wealth (and anything based on it like Signature Gear) wouldn't work. I could have it simply be granted by the regiment as a Patron, but I wanted a way to differentiate between dragoons and other Peshang who might have a lot of support from the regiment (engineers for example; who were highly valued magical practitioners). Ally seemed like the best solution.
I didn't treat IQ as n/a, because I was curious if it would break anything if I didn't and instead built the construct as an NPC with IQ and DX 0 as a 300 point character. The PC took it as an Ally with FoA of 15 or less. We never actually rolled for FoA, instead I assumed that the times in the game that the constuct was unavailable (because there are places a gentleman simply doesn't take a 500 lbs warmachine). In fairness I probably should have allowed him to take it at a lower FoA, as this ended up being more than 4.6% of the time; including a memorable fight at a dinner party where another Peshang dragoon tried to kill him while piloting an invisible construct and the PC had to make it back under fire to where his construct was parked in order to defend himself.
I handled improvements to the construct by creating some upgrade options and giving the PC the opportunity to have them installed when the construct earned enough points (at 2x the PC's increase in point total).
Overall, I think this worked really well. However this party had some pretty well defined niches and many of the characters were more-or-less noncombatants, so it's pretty hard to evaluate this as a general case. I do feel like this was actually less of a problem then the super-rich Peshang engineer character who bought TL 4+6^ armor and force fields (at x16 cost for the 4 TLs above the campaign).