Being a gearhead by inclination, I'd love to see a ship/vehicle collection. The usefulness in other editions is assured if you include deckplans and pictures. Being the first broadly
accurate collection (that didn't break design rules or be typo-ridden, or have truly awful layout) would be novel, but not necessary
If you feel more like spreading that stuff around (like GURPS:Trav has been doing) get a Safari ship into the Zoology book...