Tenants have acquired too many large vehicles

[Emily Refi]

My long-term tenants in a a town home have acquired 2 very large pick-up trucks and a sedan since signing a lease last April (it expires 4/30 this year). When they signed the lease, they listed only listed 2 vehicles - a Honda Accord, and a Dodge 2500. 

This is at a townhome at the end of a narrow, private road at the Oregon coast. There is a 1-car garage, which they don't park in, and the rest of the parking is on the private street frontage. I rent the adjacent townhome on Airbnb, and only allow 2 vehicles there.

All the huge vehicles on the street make it difficult to maneuver, and the optics look trashy on an otherwise upscale(ish) street.... ie one truck has had an old washing machine in it for 5 months. 

Is there anything I can do to set limits on vehicles before their lease expires? Besides having waaay too many pickup trucks, these tenants have been great....