You can find ship components in ruins. You may find a cache of Improved Gravitational Sensors, perhaps some 20cm Ultraviolet Lasers or just some old Cyogenic Tranport Modules. Or perhaps one or two very advanced systems. These can then be transported to a planet with shipyards and incorporated in a special class of ship. When you find components in ruins, the program will automatically add those components to the new RaceDesignTech table so you can use them in ship designs.
I have been expanding a little on this area. As I have mentioned elsewhere, ruins in In v4.3 are going back to being from different alien races. When those extinct races are created, they are also given a tech level from 1 to 5 which I will use to generate ship components. Using a subset of the NPR design code, different tech systems, such as engines, weapons, etc., are generated for that extinct race when those ship components are recovered from ruins. One generated, those designs are recorded so they can be used more than once when recovering components from the same race. This means that if you recover two sets of engines from the same ruin, or from two different ruins of the same extinct race, it will be the same engine design in both cases. If you then recover a number of laser weapons, they will be of a comparable tech level to the engines. This should add a reasonable level of internal consistency and create a feel of different technology for each extinct race.
Steve