Lucas- I'm also in SF. Purchased a 90 Troopy and arriving in January. Unfortunately, I'm going to spend about 10k to have the particulate filters installed to meet emissions standards. Per CARB, there is only one grey market "Lab" that is able to install, test, and certify that car is compliant. Below is contact information: Grey Market laboratory approved by CARB is: GNK Auto and web: G & K Automotive Services | Conversion and Modification tel: 714-545-9822 speak with George 1990 troopy is exempt DOT and federal EPA in order to register in CA, need to have CARB certification, the average cost to modify, test and certification is ~10K, parts are included: GNK will install DPF system GNK is open: M-F, near orange county.