This from Tyler Tobolt:

2 new Schaumburg ambulances to replace Ambulance 51 and 52. Photos from Foster Coach Sales, Inc facebook page. 

new ambulance for Schaumburg IL

Ambulance interior. Foster Coach Sales photo

new ambulance for Schaumburg IL

Rear of unit with no chevron striping. Foster Coach Sales photo

new ambulance for Schaumburg IL

Schuamburg Ambulance 51 on a Freightliner M2106 chassis with a Horton body. Foster Coach Sales photo

new ambulances for Schaumburg IL

Schuamburg ambulances on Freightliner M2106 chassis with Horton bodies. Foster Coach Sales photo

Webmaster note: It is unclear if these are new units or remounts.

From the Foster Coach Facebook page:

2 brand new Freightliner chassis on a custom Horton conversion with Stryker Power Load Systems.