We bought a new 2007 Siena Motorhome, within the first year it was in the shop 4 times, 2 times for leaking axle seals, 2 times for misfiring spark plugs due to not enough air flow in the spark plug area.
1st long trip we made with less than 7000 miles on the unit and 2 of the outside compartments literally melted from lack of firewall protection between catalytic converter and compartment back walls. The temperature inside the compartment was 140+ degrees and the only thing between it and the propane tank was the entry door. If it had been closer, my husband, two dogs and I could have been toast.
We trailered our car to Idaho & Washington, but couldn't climb mountains faster than 30 miles per hour over the grades. Misfiring started for the third time and spent 3 hours in Portland, OR while a wonderful repair shop installed an airflow duct system, which should have been installed after the 2nd time we had this same problem.
During this trip the slide crept out at the bottom 1-2 inches during travel.
Even though we had a pressure regulator on our water supply, the fresh water plumbing inside the motor home failed, the hose separated from the booster pump and poured water out of the compartment over the generator in copious amounts. Too pissed to write anymore about this unit..