# Error when fitting a CAR model in brms

**URL:** <https://discourse.mc-stan.org/t/error-when-fitting-a-car-model-in-brms/16687>\
**Category:** brms\
**Tags:** specification\
**Created:** [July 17, 2020, 1:46am UTC](https://discourse.mc-stan.org/t/error-when-fitting-a-car-model-in-brms/16687 "2020-07-17T01:46:10Z")\
**Posts on this page:** 1\
**Showing post:** 5

<div class="post-metadata">

**Author:** ![franzsf](https://yyz2.discourse-cdn.com/flex030/user_avatar/discourse.mc-stan.org/franzsf/32/8545_2.png) [@franzsf](https://discourse.mc-stan.org/u/franzsf)\
**Post date:** [July 17, 2020, 5:36pm UTC](https://discourse.mc-stan.org/t/error-when-fitting-a-car-model-in-brms/16687/5 "2020-07-17T17:36:13Z")

</div>

As a workaround, could one use the brms weight argument to add one made-up datapoint (i.e., population mean) per new location, and then apply zero weights to said datapoints? This could be very wrong, but it feels so right.

---

_[View the full topic](https://discourse.mc-stan.org/t/error-when-fitting-a-car-model-in-brms/16687)._