Next generation of automobiles (also known as cybercars) will increasingly incorporate electronic control units (ECUs) to implement various safety-critical functions such as x-by-wire (e.g., steer-by-wire (SBW), brake-by-wire). ISO 26262 specifies automotive safety integrity levels (ASILs) to signify the criticality associated with a function. Meeting a design’s ASIL requirements at a minimum additional cost is a major challenge in cybercar design. In this paper, we propose D2Cyber— a design automation tool for cybercars that facilitates designers in selecting dependable designs by providing built-in models, easy to specify inputs, and easy to interpret outputs. D2Cyber considers the effects of temperature, electronics quality grade, and design lifetime in cybercar’s design space exploration for determining a cost-effective solution and also advises on the attainable ASIL from a given design. We elaborate Markov models that form the basis of D2Cyber using SBW as a case study. We further provide evaluation insights obtained from D2Cyber.