Okay I’m really lost here. About a year ago I was doing deliveries in my 2016 scion iA and when I got back to my car and put it in reverse, my car started shuddering and making popping noises until it idled. This only happens when in drive or reverse. I took it to a shop and they told me I needed my entire transmission replaced but couldn’t tell me what exactly was wrong. By the time I took it to another place for a second opinion, my car was running fine again. Fast forward up until a couple days ago, my car did it again. Had it towed back to my house and by the time it was in my driveway it was running normal again. What would be causing this??? I’m honestly scared to drive my car anywhere now in fear it’ll shutter and idle again when I try to leave. Any idea at all???