State emissions test
I've taken cars for emissions testing in a couple states, but needed to do the Lotus for the first time this year. The forum provided some helpful hints on what to expect, though a number of users were in the same boat as me, i.e., "here's what it was like in my other car." Since I just completed this process a few days ago, I'll tell you exactly how it goes.
The requirement is basically every two years for most cars 5 to 30 years old in certain high-population counties. 2009+ models Cali compliant are exempt. I've been used to taking my '91 Subaru for testing in the heat of summer with no AC. It involved shutting the car off, testing the gas cap, driving it onto rollers, having a probe put into the exhaust pipe, exiting the car, and letting the attendant bring it up to a certain speed to complete the sniffer test. I didn't even know they could use OBD until my wife's newer car came due.
So, in the Lotus the other day... Step one was to get a ticket from the automated booth in the entryway. Uh, I couldn't reach it. There was no line; I looked up and someone was motioning me forward into a particular lane, though he didn't realize I didn't get the ticket yet. I put down the window and told him so. No matter.
The attendant wanted to open the door and scan a bar code which apparently was not there. I had my barcoded registration handy and that worked just fine.
At this point, I expected a gas cap test. It wouldn't have been an issue as there's no locking cap on these cars, but I swear it wasn't done. Oh well.
Now the car is shut off and he's holding the OBD plug and looking inside. I indicated the connector's location with my right hand and offered to take the plug from him with my left, not knowing if this was acceptable. No problem there. I plugged it in myself and started the car.
Just a few seconds later, all was done. I unplugged the unit, handed it back to him, and he handed me the result sheet.
Before driving forward (past those intimidating rollers), I asked if there was any danger of scraping bottom. By now, the next vehicle was a few feet behind me and backing up wasn't an option. He said it wouldn't be an issue and it wasn't. And I'm good for the next two years.
So, that's Washington state. Other states may be very similar, but feel free to tell your own story. Hope this helps someone, at least with being mentally prepared.