If you have a WRX, look no further; this is THE place to take it. Pat is a super nice and helpful guy, 100% would recommend

Went there with my 2011 Legacy gt. It had hesitation issue. They were able to figure it out and it was not easy and fix the problem. They understand Subarus. Thanks guys will be back 🙏

These guys are quick to respond, timely in services, and running an awesome business. I recommend them to anyone!

The guys were very responsive to my needs. I used them to replenish transmission fluid to my CVT, which i accidently drained out. They knew exactly what tools and supplies they needed to do in order to get the job done, because this is a job you cannot do back home. They were much cheaper than dealer. Very friendly, knowledge and professional. I highly recommend these guys.

I don’t trust bringing my q50 red sport 400 just anywhere, freshly new to the area of New Hampshire and when I tell you, nobody provides service the way they do! Very truth worthy. Best price for service compared to other location’s. Highly recommend!!!

Great shop who perform great, fast work at good prices.. just got my clutch done here on my 16 WRX by Jeremy and will be going to him for any work I need done in the future. Highly recommend.

Called To get some aftermarket parts put on my 21 WRX Pat and Jeremy were able to get me and pretty quick and did such an amazing job with my Subaru. They are very responsive superfriendly and Everything was done professionally. 603 performance is now my go to shop When I'm looking for any work done to my car I feel very fortunate to have these guys available And can't wait to work with them For my next project on my Subaru.

They installed a Fabspeed exhaust on my 2020 Audi R8 and I couldn’t be happier. Pat answered any questions that I had and I am more than satisfied with their service. I’ll be going back for any other work that I need done.

I’ve gone to Pat and Jeremy at 603 Performance a couple of times now for various aftermarket part installs on my WRX/STI. They’re quick, friendly, accommodating, and reasonably priced. They will continue to see my business anytime I need work done on my Subaru’s.

Pat and Jeremy have been my go-to mechanics ever since I discovered 603 Performance 4-5 years ago. I had an issue with my old Subie not starting in very cold weather for like 2 years. Multiple mechanics had me replace different parts and nothing worked. I missed work and a vacation trip because of it. When I found Pat he finally solved my problem, and I’ve relied on 603 ever since. I bought a brand new Subaru in 2020 and I’ve never been back to the dealer. Pat and Jeremy do all my services; everything is 100% by the book and they do not skimp on parts. Prices are very fair, I get better quality work than my dealership, and I never feel pressured. It can be hard to find a good, trustworthy mechanic. I don’t care if my next vehicle is an F150, Pat’s my guy.