Im so glad I called this place! I needed a smog check and my regular place was down for a couple…read moreweeks. So I did a quick google search and gave this place a call. The advisor that answered the phone was so nice, and said come on down! No appointment needed. I must have driven by this place a million times in the past. They have a nice waiting room with plenty of seating, front door open for fresh air, both advisors working inside super nice and helpful. He took my keys and started on my truck right away, which I definitely wasn't expecting! He gave me a time frame before I even had to ask! I hung out and played games on my phone. Totally chill in here. . Anddddddd they have a $10 smog coupon on their website they let me use. Overall, awesome experience! I'll absolutely be back and recommend these gentlemen! Thanks guys!

They are very polite. Professional. I did not have an appointment but he took my car right away…read moreand did my smog check. I was in and out very quickly. I have gone there for years and they are always great.

10 out of 10 stars the crew aint playing all business when…read moreit comes to fixing cars got my front brake pads rotors done on my bmw treated with respectfully and foremost no up selling had me out there in under a hour. if you want a trusted mechanic this is the spot . thank you team you guys did and outstanding job will be back. 1-30-26.

Walt from Walt's Adventures in Concord, California. State approved vehicles allow me to travel…read morefrom one adventure to the next. Smog checks are necessary for California. Super Station on Monument was professional, quick, and I would recommend them.

Excellent, fast, and friendly service! Called on a Tuesday around 12:40pm to book a same day…read moreappointment for a Smog check and was able to get one. I needed to get a Smog certification to get my car registration renewed, and Walnut Creek Smog made the process easy! Check in was quick, and the Smog check was completed in 15 minutes as promised. I've been here twice now, and I'll definitely be back in the future!

This is a hidden gem! I tried to get a smog done at another local shop and when they couldn't take…read moremy car for the second time I jumped on Yelp to find someone who could get my car. My first call was to Walnut Creek Smog and they told me they needed to calibrate the machine and to come in an hour. I showed up and was greeted and they quickly got to work. They smogged my car quickly and were priced fairly. The employee who helped me was super friendly. They just won us over as new customers!

I have used Star Smog many times for my vehicles. Always quick and very convenient. Sophia always…read moregreets with a smile and very helpful!

My go to place to get quick and reliable service. Conveniently located near downtown and plenty of…read moreparking spots! If you need to get your car smogged, and don't want to waste time on it being done, this is the place to go.

Called the same day and talked to the owner who was fantastic. I said I needed a smog check done on…read moremy car and he said I could come in the same day. I paid $65ish because they were running a promotion. I would definitely recommend them to anyone who needs theirs done. Thank you!

I had expressed a window of time i would be by, and ended up being being a bit late…read more i didn't have to wait e 5 minutes, until my car was in the bay, and the entire process was done within 15 minutes from the time i arrived. Sam was so pleasant and helpful! i missplaced my phone and he called it and i had it back in hand immediately. he had offered a coupon and remembered that when he was checking me out. he we far and above what i have experienced at other places. I will definitely be back next time i need a star smog! 5*****

Clayton auto services has been extremely helpful. I have taken my cars to them multiple times; they…read moreare quick, do high quality work, and are very reasonably priced! If you want quality work at a great value, go to Clayton auto service!

I've been coming to Clayton Auto Service for about 2 years now and have been very pleased with the…read morequality of work performed here. I need my car for work and there was a time it was disabled by a failing alternator. I stressed to Irfan and his team that I needed my car repaired quick. Irfan was receptive to this and really went above and beyond to get it repaired and in a timely manner. On a separate occasion, they fixed a radiator leak, replaced my catalytic converters, and did my smog testing. The whole process was smooth and professional. They were honest, efficient, and did quality work. I'll definitely be coming back for future repairs and highly recommend them to anyone looking for a trustworthy auto shop.

Great service and he was quick and efficient now I'm just typing eighty five charactersread more

Took my friend to get her car smogged a few days ago and it was finished within 45 mins. Quick…read moreservice and great customer service! Thank you!

Elite craftsmanship, honest leadership, and true car people…read more This shop is the definition of how an automotive business should be run. Sami, the owner, brings a level of experience and integrity that's rare today. You can tell immediately he's not interested in shortcuts -- only in doing the job correctly, responsibly, and with long-term ownership in mind. That mindset flows through the entire operation. Amal is equally impressive. She's professional, knowledgeable, and incredibly organized, making communication smooth and transparent from start to finish. Together, they've built a shop that runs efficiently while still treating every car with genuine care and respect. They previously handled a major drivetrain project for me (BMW E38 M62TU swap), and the execution was flawless -- clean work, fair pricing, and no surprises. That level of trust is hard to earn. Because of that experience, I'm now confidently bringing them another special vehicle for a full recommissioning. I wouldn't do that if there were even the slightest doubt. If you're an enthusiast, collector, or simply someone who values honest work done right the first time, this is the shop you want. Sami and Amal run an operation that sets the standard. ( Sami also has a pristine Carrera 993 air cooled ) Highly recommended.

Hello out there. I had another great experience at Concord Smog, Tune and Brakes yesterday. I…read morehave been going to them for years now, back when Ray owned the business, then on to Sammy and now with Sammy's daughter, Amal. I take all of my family vehicles there for oil changes and transmission service, brake jobs and smog checks, which are the bread and butter for their shop. Quality work, very fair prices and wonderful customer service. I highly recommend them!! Let's keep them going! Paul R.