<PAGE>

                                                                    Exhibit 10.6

                        SENIOR SECURED SUBORDINATED NOTE

         THIS INSTRUMENT AND THE RIGHTS AND OBLIGATIONS EVIDENCED HEREBY ARE
         SUBORDINATE IN THE MANNER AND TO THE EXTENT SET FORTH IN THAT CERTAIN
         SUBORDINATION AGREEMENT (AS AMENDED, THE "SUBORDINATION AGREEMENT")
         DATED AS OF MARCH 30, 2004 AMONG AMERICAN CAPITAL FINANCIAL SERVICES,
         INC., AMERICAN CAPITAL STRATEGIES, LTD., CORRPRO COMPANIES, INC., THE
         OTHER OBLIGORS (AS DEFINED THEREIN) AND CAPITALSOURCE FINANCE LLC, AS
         AGENT TO THE SENIOR DEBT (AS DEFINED THEREIN), AS MORE PARTICULARLY
         DESCRIBED IN THE SUBORDINATION AGREEMENT, AND EACH HOLDER OF THIS
         INSTRUMENT, BY ITS ACCEPTANCE HEREOF, SHALL BE BOUND BY THE PROVISIONS
         OF THE SUBORDINATION AGREEMENT.

         THIS NOTE HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS
         AMENDED, OR UNDER THE SECURITIES LAWS OF ANY STATE. THIS NOTE HAS BEEN
         ACQUIRED FOR INVESTMENT PURPOSES AND NOT WITH A VIEW TO DISTRIBUTION,
         AND NO TRANSFER, SALE OR OTHER DISPOSITION OF THIS NOTE MAY BE MADE
         UNLESS A REGISTRATION STATEMENT WITH RESPECT TO THIS NOTE HAS BECOME
         EFFECTIVE UNDER SUCH ACT, AND SUCH REGISTRATION OR QUALIFICATION AS MAY
         BE NECESSARY UNDER THE SECURITIES LAWS OF ANY STATE HAS BECOME
         EFFECTIVE, OR SUCH REGISTRATION IS NOT REQUIRED.

           FORM OF SENIOR SECURED SUBORDINATED NOTE DUE MARCH 29, 2011

$__________________________                                       March 30, 2004

                  FOR VALUE RECEIVED, the undersigned, CORRPRO COMPANIES, INC.,
an Ohio corporation, CCFC, INC., a Nevada corporation, OCEAN CITY RESEARCH
CORP., a New Jersey corporation, and CORRPRO INTERNATIONAL, INC., f/k/a Corrpro
Companies Latin America, Inc., a Delaware corporation (collectively, together
with their successors and assigns, the "Company"), jointly and severally, hereby
promises to pay to AMERICAN CAPITAL STRATEGIES, LTD. or its registered
assigns (the "Holder") the principal sum of _______________ Dollars ($______ ),
with interest thereon, on the terms and conditions set forth in the Purchase
Agreement (as defined herein).

                  Payments of principal of, interest on and any premium with
respect to this Senior Secured Subordinated Note are to be made in accordance
with Article 3 and Annex A of the Purchase Agreement and in lawful money of the
United States of America.

                  Notwithstanding any provision to the contrary in this Senior
Secured Subordinated Note, the Purchase Agreement or any other agreement, the
Company shall not be required to pay, and the Holder shall not be permitted to
contract for, take, reserve, charge or receive, any compensation which
constitutes interest under applicable law in excess of the maximum amount of
interest permitted by law.

<PAGE>

                  This Senior Secured Subordinated Note is one of a series of
Senior Secured Subordinated Notes due March 29, 2011 issued pursuant to the Note
and Equity Purchase Agreement, dated as of March 30, 2004 (as from time to time
amended, the "Purchase Agreement"), among the Company, Commonwealth Seager
Holdings Ltd., Corrpro Canada, Inc., Borza Inspections Ltd., American Capital
Financial Services, Inc., American Capital Strategies, Ltd. and the other
purchasers named therein, and is entitled to the benefits thereof. All initially
capitalized terms used herein but not defined herein shall have the meanings
ascribed to them in the Purchase Agreement. Each Holder of this Senior Secured
Subordinated Note will be deemed, by its acceptance hereof, to have agreed to
the provisions and to have made the representations and warranties set forth in
Section 6.2 of the Purchase Agreement.

                  This Senior Secured Subordinated Note is transferable only in
accordance with the terms of the Purchase Agreement.

                  This Senior Secured Subordinated Note is also subject to
mandatory and optional prepayment, in whole or from time to time in part, at the
times and on the terms specified in the Purchase Agreement, but not otherwise.

                  If an Event of Default occurs and is continuing, among the
other consequences thereof set forth in the Purchase Agreement and otherwise,
the unpaid principal of this Senior Secured Subordinated Note, and the interest
accrued thereon, may be declared or otherwise become due and payable in the
manner, at the price (including any applicable premium) and with the effect
provided in the Purchase Agreement.

The Company hereby unconditionally waives any and all right to presentment,
demand, protest or notice of any kind (except as expressly required hereby or by
the Purchase Agreement) and any defenses to payment and/or any rights to setoff
payment that the Company may have against the Holder or any other person,
including any person who assigned this Senior Secured Subordinated Note to the
Holder.

                  Payments of principal, interest on and any premium with
respect to this Senior Secured Subordinated Note are secured pursuant to the
terms of the Security Documents (as defined in the Purchase Agreement).

                  This Senior Secured Subordinated Note and the rights and
obligations of the parties hereto shall be deemed to be contracts under the laws
of the State of New York and for all purposes shall be governed by and construed
and enforced in accordance with the laws of said State, except for its rules
relating to the conflict of laws.

         [REMAINDER OF PAGE INTENTIONALLY BLANK; SIGNATURE PAGE FOLLOWS]

                                       2

<PAGE>

The undersigned has executed this Senior Secured Subordinated Note as of the
date first written above.

                                               CORRPRO COMPANIES, INC.

                                               By:
                                                  ------------------------------
                                                  Robert M. Mayer
                                                  Chief Financial Officer

                                               CCFC, INC.

                                               By:
                                                  ------------------------------
                                                  Robert M. Mayer
                                                  Treasurer

                                               OCEAN CITY RESEARCH CORP.

                                               By:
                                                  ------------------------------
                                                  Robert M. Mayer
                                                  Treasurer

                                               CORRPRO INTERNATIONAL, INC.

                                               By:
                                                  ------------------------------
                                                  Robert M. Mayer
                                                  Treasurer